121563640540 has 96 divisors (see below), whose sum is σ = 261351014400. Its totient is φ = 47485751040.

The previous prime is 121563640493. The next prime is 121563640547. The reversal of 121563640540 is 45046365121.

It is a self number, because there is not a number n which added to its sum of digits gives 121563640540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121563640547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84477141 + ... + 84478579.

It is an arithmetic number, because the mean of its divisors is an integer number (2722406400).

Almost surely, 2^121563640540 is an apocalyptic number.

121563640540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121563640540 is an abundant number, since it is smaller than the sum of its proper divisors (139787373860).

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

121563640540 is a wasteful number, since it uses less digits than its factorization.

121563640540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075 (or 2073 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 121563640540 in words is "one hundred twenty-one billion, five hundred sixty-three million, six hundred forty thousand, five hundred forty".