21490260628 has 6 divisors (see below), whose sum is σ = 37607956106. Its totient is φ = 10745130312.

The previous prime is 21490260619. The next prime is 21490260661. The reversal of 21490260628 is 82606209412.

It can be written as a sum of positive squares in only one way, i.e., 13567124484 + 7923136144 = 116478^2 + 89012^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2686282575 + ... + 2686282582.

Almost surely, 2^21490260628 is an apocalyptic number.

It is an amenable number.

21490260628 is a deficient number, since it is larger than the sum of its proper divisors (16117695478).

21490260628 is a wasteful number, since it uses less digits than its factorization.

21490260628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5372565161 (or 5372565159 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The spelling of 21490260628 in words is "twenty-one billion, four hundred ninety million, two hundred sixty thousand, six hundred twenty-eight".