21726449956 has 24 divisors (see below), whose sum is σ = 40462213176. Its totient is φ = 10172305920.

The previous prime is 21726449951. The next prime is 21726449963. The reversal of 21726449956 is 65994462712.

It can be written as a sum of positive squares in 4 ways, for example, as 4548153600 + 17178296356 = 67440^2 + 131066^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21726449897 and 21726449906.

It is not an unprimeable number, because it can be changed into a prime (21726449951) 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, 797535 + ... + 824326.

It is an arithmetic number, because the mean of its divisors is an integer number (1685925549).

Almost surely, 2^21726449956 is an apocalyptic number.

It is an amenable number.

21726449956 is a deficient number, since it is larger than the sum of its proper divisors (18735763220).

21726449956 is a wasteful number, since it uses less digits than its factorization.

21726449956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622079 (or 1622077 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 55.

The spelling of 21726449956 in words is "twenty-one billion, seven hundred twenty-six million, four hundred forty-nine thousand, nine hundred fifty-six".