121655621340 has 144 divisors (see below), whose sum is σ = 426250188000. Its totient is φ = 27757424640.

The previous prime is 121655621327. The next prime is 121655621359. The reversal of 121655621340 is 43126556121.

121655621340 is a `hidden beast` number, since 1 + 2 + 1 + 65 + 562 + 1 + 34 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 121655621295 and 121655621304.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1773465 + ... + 1840784.

It is an arithmetic number, because the mean of its divisors is an integer number (2960070750).

Almost surely, 2^121655621340 is an apocalyptic number.

121655621340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121655621340 is an abundant number, since it is smaller than the sum of its proper divisors (304594566660).

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

121655621340 is a wasteful number, since it uses less digits than its factorization.

121655621340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3614292 (or 3614287 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 121655621340 in words is "one hundred twenty-one billion, six hundred fifty-five million, six hundred twenty-one thousand, three hundred forty".