21007764485 has 16 divisors (see below), whose sum is σ = 26631955200. Its totient is φ = 15864175296.

The previous prime is 21007764431. The next prime is 21007764487. The reversal of 21007764485 is 58446770012.

It is a cyclic number.

It is not a de Polignac number, because 21007764485 - 2²⁸ = 20739329029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21007764487) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 372845 + ... + 425474.

It is an arithmetic number, because the mean of its divisors is an integer number (1664497200).

Almost surely, 2^21007764485 is an apocalyptic number.

It is an amenable number.

21007764485 is a deficient number, since it is larger than the sum of its proper divisors (5624190715).

21007764485 is a wasteful number, since it uses less digits than its factorization.

21007764485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798620.

The product of its (nonzero) digits is 376320, while the sum is 44.

The spelling of 21007764485 in words is "twenty-one billion, seven million, seven hundred sixty-four thousand, four hundred eighty-five".