21575437684 has 48 divisors (see below), whose sum is σ = 40058032896. Its totient is φ = 10146752000.

The previous prime is 21575437679. The next prime is 21575437727. The reversal of 21575437684 is 48673457512.

It is a super-2 number, since 2×21575437684² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2615214 + ... + 2623450.

It is an arithmetic number, because the mean of its divisors is an integer number (834542352).

Almost surely, 2^21575437684 is an apocalyptic number.

It is an amenable number.

21575437684 is a deficient number, since it is larger than the sum of its proper divisors (18482595212).

21575437684 is a wasteful number, since it uses less digits than its factorization.

21575437684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8736 (or 8734 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 52.

The spelling of 21575437684 in words is "twenty-one billion, five hundred seventy-five million, four hundred thirty-seven thousand, six hundred eighty-four".