21437378552 has 8 divisors (see below), whose sum is σ = 40195084800. Its totient is φ = 10718689272.

The previous prime is 21437378507. The next prime is 21437378561. The reversal of 21437378552 is 25587373412.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21437378552² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21437378497 and 21437378506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1339836152 + ... + 1339836167.

It is an arithmetic number, because the mean of its divisors is an integer number (5024385600).

Almost surely, 2^21437378552 is an apocalyptic number.

It is an amenable number.

21437378552 is a deficient number, since it is larger than the sum of its proper divisors (18757706248).

21437378552 is a wasteful number, since it uses less digits than its factorization.

21437378552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2679672325 (or 2679672321 counting only the distinct ones).

The product of its digits is 1411200, while the sum is 47.

The spelling of 21437378552 in words is "twenty-one billion, four hundred thirty-seven million, three hundred seventy-eight thousand, five hundred fifty-two".