21040792878 has 64 divisors (see below), whose sum is σ = 49793886720. Its totient is φ = 5799427200.

The previous prime is 21040792853. The next prime is 21040792921. The reversal of 21040792878 is 87829704012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1565748 + ... + 1579128.

It is an arithmetic number, because the mean of its divisors is an integer number (778029480).

Almost surely, 2^21040792878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21040792878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24896943360).

21040792878 is an abundant number, since it is smaller than the sum of its proper divisors (28753093842).

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

21040792878 is a wasteful number, since it uses less digits than its factorization.

21040792878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14713.

The product of its (nonzero) digits is 451584, while the sum is 48.

The spelling of 21040792878 in words is "twenty-one billion, forty million, seven hundred ninety-two thousand, eight hundred seventy-eight".