21364400615 has 16 divisors (see below), whose sum is σ = 26118819360. Its totient is φ = 16771539840.

The previous prime is 21364400597. The next prime is 21364400657. The reversal of 21364400615 is 51600446312.

It is not a de Polignac number, because 21364400615 - 2²⁶ = 21297291751 is a prime.

It is a super-2 number, since 2×21364400615² (a number of 21 digits) contains 22 as substring.

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, 99305 + ... + 229325.

It is an arithmetic number, because the mean of its divisors is an integer number (1632426210).

Almost surely, 2^21364400615 is an apocalyptic number.

21364400615 is a deficient number, since it is larger than the sum of its proper divisors (4754418745).

21364400615 is a wasteful number, since it uses less digits than its factorization.

21364400615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130642.

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 21364400615 its reverse (51600446312), we get a palindrome (72964846927).

The spelling of 21364400615 in words is "twenty-one billion, three hundred sixty-four million, four hundred thousand, six hundred fifteen".