121947291648 has 528 divisors, whose sum is σ = 439697172096. Its totient is φ = 31708938240.

The previous prime is 121947291647. The next prime is 121947291701. The reversal of 121947291648 is 846192749121.

121947291648 is a `hidden beast` number, since 1 + 2 + 1 + 9 + 472 + 9 + 164 + 8 = 666.

It is a super-2 number, since 2×121947291648² (a number of 23 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (1741824) is a multiple of the sum of its prime divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 121947291594 and 121947291603.

It is not an unprimeable number, because it can be changed into a prime (121947291643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1717567453 + ... + 1717567523.

Almost surely, 2^121947291648 is an apocalyptic number.

121947291648 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121947291648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219848586048).

121947291648 is an abundant number, since it is smaller than the sum of its proper divisors (317749880448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121947291648 is an frugal number, since it uses more digits than its factorization.

121947291648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 96 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

It can be divided in two parts, 121947 and 291648, that added together give a triangular number (413595 = T₉₀₉).

The spelling of 121947291648 in words is "one hundred twenty-one billion, nine hundred forty-seven million, two hundred ninety-one thousand, six hundred forty-eight".