21401515515 has 8 divisors (see below), whose sum is σ = 34242424848. Its totient is φ = 11414141600.

The previous prime is 21401515459. The next prime is 21401515547. The reversal of 21401515515 is 51551510412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21401515515 - 2⁸ = 21401515259 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 713383836 + ... + 713383865.

It is an arithmetic number, because the mean of its divisors is an integer number (4280303106).

Almost surely, 2^21401515515 is an apocalyptic number.

21401515515 is a deficient number, since it is larger than the sum of its proper divisors (12840909333).

21401515515 is a wasteful number, since it uses less digits than its factorization.

21401515515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426767709.

The product of its (nonzero) digits is 5000, while the sum is 30.

The spelling of 21401515515 in words is "twenty-one billion, four hundred one million, five hundred fifteen thousand, five hundred fifteen".