21154520611015 has 16 divisors (see below), whose sum is σ = 28337218310016. Its totient is φ = 15027312736800.

The previous prime is 21154520610973. The next prime is 21154520611051. The reversal of 21154520611015 is 51011602545112.

It is not a de Polignac number, because 21154520611015 - 2⁴¹ = 18955497355463 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4472412141 + ... + 4472416870.

It is an arithmetic number, because the mean of its divisors is an integer number (1771076144376).

Almost surely, 2^{21154520611015} is an apocalyptic number.

21154520611015 is a deficient number, since it is larger than the sum of its proper divisors (7182697699001).

21154520611015 is a wasteful number, since it uses less digits than its factorization.

21154520611015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8944829070.

The product of its (nonzero) digits is 12000, while the sum is 34.

The spelling of 21154520611015 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred twenty million, six hundred eleven thousand, fifteen".