21011506715 has 8 divisors (see below), whose sum is σ = 25237850400. Its totient is φ = 16793177152.

The previous prime is 21011506667. The next prime is 21011506727. The reversal of 21011506715 is 51760511012.

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

It is a cyclic number.

It is not a de Polignac number, because 21011506715 - 2²² = 21007312411 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, 1997759 + ... + 2008248.

It is an arithmetic number, because the mean of its divisors is an integer number (3154731300).

Almost surely, 2^21011506715 is an apocalyptic number.

21011506715 is a deficient number, since it is larger than the sum of its proper divisors (4226343685).

21011506715 is a wasteful number, since it uses less digits than its factorization.

21011506715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4007061.

The product of its (nonzero) digits is 2100, while the sum is 29.

The spelling of 21011506715 in words is "twenty-one billion, eleven million, five hundred six thousand, seven hundred fifteen".