21054688878 has 8 divisors (see below), whose sum is σ = 42109377768. Its totient is φ = 7018229624.

The previous prime is 21054688859. The next prime is 21054688901. The reversal of 21054688878 is 87888645012.

It is a sphenic number, since it is the product of 3 distinct primes.

21054688878 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1754557401 + ... + 1754557412.

It is an arithmetic number, because the mean of its divisors is an integer number (5263672221).

Almost surely, 2^21054688878 is an apocalyptic number.

21054688878 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21054688878 is a wasteful number, since it uses less digits than its factorization.

21054688878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3509114818.

The product of its (nonzero) digits is 6881280, while the sum is 57.

The spelling of 21054688878 in words is "twenty-one billion, fifty-four million, six hundred eighty-eight thousand, eight hundred seventy-eight".