21174067640 has 64 divisors (see below), whose sum is σ = 53649285120. Its totient is φ = 7451280000.

The previous prime is 21174067639. The next prime is 21174067693. The reversal of 21174067640 is 4676047112.

It is a happy number.

It is a super-2 number, since 2×21174067640² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21174067594 and 21174067603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 762536 + ... + 789815.

It is an arithmetic number, because the mean of its divisors is an integer number (838270080).

Almost surely, 2^21174067640 is an apocalyptic number.

21174067640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21174067640 is an abundant number, since it is smaller than the sum of its proper divisors (32475217480).

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

21174067640 is a wasteful number, since it uses less digits than its factorization.

21174067640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1552404 (or 1552400 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 38.

The spelling of 21174067640 in words is "twenty-one billion, one hundred seventy-four million, sixty-seven thousand, six hundred forty".