21726891370 has 16 divisors (see below), whose sum is σ = 39115250568. Its totient is φ = 8689235200.

The previous prime is 21726891359. The next prime is 21726891427. The reversal of 21726891370 is 7319862712.

It can be written as a sum of positive squares in 4 ways, for example, as 21711138409 + 15752961 = 147347^2 + 3969^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21726891370.

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, 129259 + ... + 245278.

Almost surely, 2^21726891370 is an apocalyptic number.

21726891370 is a deficient number, since it is larger than the sum of its proper divisors (17388359198).

21726891370 is a wasteful number, since it uses less digits than its factorization.

21726891370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380345.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 21726891370 in words is "twenty-one billion, seven hundred twenty-six million, eight hundred ninety-one thousand, three hundred seventy".