121639206543840 has 384 divisors, whose sum is σ = 444367708646400. Its totient is φ = 31018419210240.

The previous prime is 121639206543809. The next prime is 121639206543847. The reversal of 121639206543840 is 48345602936121.

It is a happy number.

121639206543840 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 3 + 9 + 206 + 54 + 384 + 0 = 666.

It is a super-2 number, since 2×121639206543840² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121639206543847) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 371343330 + ... + 371670750.

It is an arithmetic number, because the mean of its divisors is an integer number (1157207574600).

Almost surely, 2^{121639206543840} is an apocalyptic number.

121639206543840 is a gapful number since it is divisible by the number (10) 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 121639206543840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (222183854323200).

121639206543840 is an abundant number, since it is smaller than the sum of its proper divisors (322728502102560).

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

121639206543840 is a wasteful number, since it uses less digits than its factorization.

121639206543840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331207 (or 331193 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 121639206543840 in words is "one hundred twenty-one trillion, six hundred thirty-nine billion, two hundred six million, five hundred forty-three thousand, eight hundred forty".