21154520611016 has 16 divisors (see below), whose sum is σ = 42715858926300. Its totient is φ = 9763624897344.

The previous prime is 21154520610973. The next prime is 21154520611051. The reversal of 21154520611016 is 61011602545112.

It can be written as a sum of positive squares in 2 ways, for example, as 19410668308516 + 1743852302500 = 4405754^2 + 1320550^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101704425911 + ... + 101704426118.

Almost surely, 2^{21154520611016} is an apocalyptic number.

21154520611016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21154520611016 is an abundant number, since it is smaller than the sum of its proper divisors (21561338315284).

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

21154520611016 is a wasteful number, since it uses less digits than its factorization.

21154520611016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203408852048 (or 203408852044 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 35.

The spelling of 21154520611016 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred twenty million, six hundred eleven thousand, sixteen".