21214017515 has 16 divisors (see below), whose sum is σ = 25804880640. Its totient is φ = 16740728160.

The previous prime is 21214017479. The next prime is 21214017523. The reversal of 21214017515 is 51571041212.

It is not a de Polignac number, because 21214017515 - 2⁸ = 21214017259 is a prime.

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, 12416 + ... + 206354.

It is an arithmetic number, because the mean of its divisors is an integer number (1612805040).

Almost surely, 2^21214017515 is an apocalyptic number.

21214017515 is a deficient number, since it is larger than the sum of its proper divisors (4590863125).

21214017515 is a wasteful number, since it uses less digits than its factorization.

21214017515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194242.

The product of its (nonzero) digits is 2800, while the sum is 29.

Adding to 21214017515 its reverse (51571041212), we get a palindrome (72785058727).

The spelling of 21214017515 in words is "twenty-one billion, two hundred fourteen million, seventeen thousand, five hundred fifteen".