21154520613616 has 40 divisors (see below), whose sum is σ = 45332686341824. Its totient is φ = 9499743141120.

The previous prime is 21154520613601. The next prime is 21154520613617. The reversal of 21154520613616 is 61631602545112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154520613617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1374376440 + ... + 1374391831.

Almost surely, 2^{21154520613616} is an apocalyptic number.

21154520613616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21154520613616 is an abundant number, since it is smaller than the sum of its proper divisors (24178165728208).

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

21154520613616 is a wasteful number, since it uses less digits than its factorization.

21154520613616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2748768329 (or 2748768323 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 21154520613616 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred twenty million, six hundred thirteen thousand, six hundred sixteen".