21393500215 has 16 divisors (see below), whose sum is σ = 25750561536. Its totient is φ = 17062617600.

The previous prime is 21393500201. The next prime is 21393500237. The reversal of 21393500215 is 51200539312.

It is not a de Polignac number, because 21393500215 - 2¹⁹ = 21392975927 is a prime.

It is a Duffinian number.

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, 4546554 + ... + 4551256.

It is an arithmetic number, because the mean of its divisors is an integer number (1609410096).

Almost surely, 2^21393500215 is an apocalyptic number.

21393500215 is a deficient number, since it is larger than the sum of its proper divisors (4357061321).

21393500215 is a wasteful number, since it uses less digits than its factorization.

21393500215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7290.

The product of its (nonzero) digits is 8100, while the sum is 31.

The spelling of 21393500215 in words is "twenty-one billion, three hundred ninety-three million, five hundred thousand, two hundred fifteen".