21365220370 has 64 divisors (see below), whose sum is σ = 42517689984. Its totient is φ = 7679992320.

The previous prime is 21365220353. The next prime is 21365220403. The reversal of 21365220370 is 7302256312.

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, 1743565 + ... + 1755775.

It is an arithmetic number, because the mean of its divisors is an integer number (664338906).

Almost surely, 2^21365220370 is an apocalyptic number.

21365220370 is a deficient number, since it is larger than the sum of its proper divisors (21152469614).

21365220370 is a wasteful number, since it uses less digits than its factorization.

21365220370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12587.

The product of its (nonzero) digits is 15120, while the sum is 31.

Adding to 21365220370 its reverse (7302256312), we get a palindrome (28667476682).

The spelling of 21365220370 in words is "twenty-one billion, three hundred sixty-five million, two hundred twenty thousand, three hundred seventy".