21247911996 has 48 divisors (see below), whose sum is σ = 52426042368. Its totient is φ = 6686985600.

The previous prime is 21247911943. The next prime is 21247912031. The reversal of 21247911996 is 69911974212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 681310 + ... + 711813.

It is an arithmetic number, because the mean of its divisors is an integer number (1092209216).

Almost surely, 2^21247911996 is an apocalyptic number.

It is an amenable number.

21247911996 is an abundant number, since it is smaller than the sum of its proper divisors (31178130372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21247911996 is a wasteful number, since it uses less digits than its factorization.

21247911996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1393202 (or 1393200 counting only the distinct ones).

The product of its digits is 489888, while the sum is 51.

The spelling of 21247911996 in words is "twenty-one billion, two hundred forty-seven million, nine hundred eleven thousand, nine hundred ninety-six".