21185974677504 has 1248 divisors, whose sum is σ = 75788497956864. Its totient is φ = 5119648727040.

The previous prime is 21185974677493. The next prime is 21185974677509. The reversal of 21185974677504 is 40577647958112.

It is a tau number, because it is divible by the number of its divisors (1248).

It is not an unprimeable number, because it can be changed into a prime (21185974677509) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12513864882 + ... + 12513866574.

Almost surely, 2^{21185974677504} is an apocalyptic number.

21185974677504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21185974677504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37894248978432).

21185974677504 is an abundant number, since it is smaller than the sum of its proper divisors (54602523279360).

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

21185974677504 is a wasteful number, since it uses less digits than its factorization.

21185974677504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1809 (or 1768 counting only the distinct ones).

The product of its (nonzero) digits is 118540800, while the sum is 66.

The spelling of 21185974677504 in words is "twenty-one trillion, one hundred eighty-five billion, nine hundred seventy-four million, six hundred seventy-seven thousand, five hundred four".