21547963970 has 16 divisors (see below), whose sum is σ = 41769899640. Its totient is φ = 7956171264.

The previous prime is 21547963951. The next prime is 21547963979. The reversal of 21547963970 is 7936974512.

It can be written as a sum of positive squares in 4 ways, for example, as 15530393641 + 6017570329 = 124621^2 + 77573^2 .

It is not an unprimeable number, because it can be changed into a prime (21547963979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82876655 + ... + 82876914.

Almost surely, 2^21547963970 is an apocalyptic number.

21547963970 is a deficient number, since it is larger than the sum of its proper divisors (20221935670).

21547963970 is a wasteful number, since it uses less digits than its factorization.

21547963970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165753589.

The product of its (nonzero) digits is 2857680, while the sum is 53.

The spelling of 21547963970 in words is "twenty-one billion, five hundred forty-seven million, nine hundred sixty-three thousand, nine hundred seventy".