21245514972 has 48 divisors (see below), whose sum is σ = 55398518784. Its totient is φ = 6281008000.

The previous prime is 21245514971. The next prime is 21245515037. The reversal of 21245514972 is 27941554212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245514971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1957404 + ... + 1968227.

It is an arithmetic number, because the mean of its divisors is an integer number (1154135808).

Almost surely, 2^21245514972 is an apocalyptic number.

21245514972 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21245514972 is an abundant number, since it is smaller than the sum of its proper divisors (34153003812).

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

21245514972 is a wasteful number, since it uses less digits than its factorization.

21245514972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3925690 (or 3925688 counting only the distinct ones).

The product of its digits is 201600, while the sum is 42.

The spelling of 21245514972 in words is "twenty-one billion, two hundred forty-five million, five hundred fourteen thousand, nine hundred seventy-two".