21154520613615 has 32 divisors (see below), whose sum is σ = 33916905792000. Its totient is φ = 11259189188736.

The previous prime is 21154520613601. The next prime is 21154520613617. The reversal of 21154520613615 is 51631602545112.

It is not a de Polignac number, because 21154520613615 - 2¹³ = 21154520605423 is a prime.

It is a super-2 number, since 2×21154520613615² (a number of 27 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159985669 + ... + 160117841.

It is an arithmetic number, because the mean of its divisors is an integer number (1059903306000).

Almost surely, 2^{21154520613615} is an apocalyptic number.

21154520613615 is a deficient number, since it is larger than the sum of its proper divisors (12762385178385).

21154520613615 is a wasteful number, since it uses less digits than its factorization.

21154520613615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154063.

The product of its (nonzero) digits is 216000, while the sum is 42.

The spelling of 21154520613615 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred twenty million, six hundred thirteen thousand, six hundred fifteen".