121553665632 has 384 divisors, whose sum is σ = 433127761920. Its totient is φ = 32407879680.

The previous prime is 121553665573. The next prime is 121553665697. The reversal of 121553665632 is 236566355121.

121553665632 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 5 + 3 + 6 + 6 + 5 + 632 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5692608 + ... + 5713920.

It is an arithmetic number, because the mean of its divisors is an integer number (1127936880).

Almost surely, 2^121553665632 is an apocalyptic number.

121553665632 is a gapful number since it is divisible by the number (12) 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 121553665632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216563880960).

121553665632 is an abundant number, since it is smaller than the sum of its proper divisors (311574096288).

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

121553665632 is a wasteful number, since it uses less digits than its factorization.

121553665632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21403 (or 21389 counting only the distinct ones).

The product of its digits is 972000, while the sum is 45.

The spelling of 121553665632 in words is "one hundred twenty-one billion, five hundred fifty-three million, six hundred sixty-five thousand, six hundred thirty-two".