21507735180072 has 32 divisors (see below), whose sum is σ = 54680682664800. Its totient is φ = 7047732431424.

The previous prime is 21507735180053. The next prime is 21507735180091. The reversal of 21507735180072 is 27008153770512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21507735180053) and next prime (21507735180091).

It is a super-2 number, since 2×21507735180072² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7594537843 + ... + 7594540674.

It is an arithmetic number, because the mean of its divisors is an integer number (1708771333275).

Almost surely, 2^{21507735180072} is an apocalyptic number.

It is an amenable number.

21507735180072 is an abundant number, since it is smaller than the sum of its proper divisors (33172947484728).

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

21507735180072 is a wasteful number, since it uses less digits than its factorization.

21507735180072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15189078585 (or 15189078581 counting only the distinct ones).

The product of its (nonzero) digits is 823200, while the sum is 48.

The spelling of 21507735180072 in words is "twenty-one trillion, five hundred seven billion, seven hundred thirty-five million, one hundred eighty thousand, seventy-two".