21056456510 has 64 divisors (see below), whose sum is σ = 39533961600. Its totient is φ = 8068300800.

The previous prime is 21056456437. The next prime is 21056456527. The reversal of 21056456510 is 1565465012.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7829246 + ... + 7831934.

It is an arithmetic number, because the mean of its divisors is an integer number (617718150).

Almost surely, 2^21056456510 is an apocalyptic number.

21056456510 is a deficient number, since it is larger than the sum of its proper divisors (18477505090).

21056456510 is a wasteful number, since it uses less digits than its factorization.

21056456510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3077.

The product of its (nonzero) digits is 36000, while the sum is 35.

The spelling of 21056456510 in words is "twenty-one billion, fifty-six million, four hundred fifty-six thousand, five hundred ten".