21501340944 has 20 divisors (see below), whose sum is σ = 55545130896. Its totient is φ = 7167113632.

The previous prime is 21501340901. The next prime is 21501340957. The reversal of 21501340944 is 44904310512.

It is a super-2 number, since 2×21501340944² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223972254 + ... + 223972349.

Almost surely, 2^21501340944 is an apocalyptic number.

21501340944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21501340944 is an abundant number, since it is smaller than the sum of its proper divisors (34043789952).

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

21501340944 is a wasteful number, since it uses less digits than its factorization.

21501340944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447944614 (or 447944608 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 21501340944 in words is "twenty-one billion, five hundred one million, three hundred forty thousand, nine hundred forty-four".