20978776 has 32 divisors (see below), whose sum is σ = 48414240. Its totient is φ = 8299008.

The previous prime is 20978773. The next prime is 20978791. The reversal of 20978776 is 67787902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20978773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13681 + ... + 15136.

It is an arithmetic number, because the mean of its divisors is an integer number (1512945).

Almost surely, 2^20978776 is an apocalyptic number.

20978776 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20978776 is an abundant number, since it is smaller than the sum of its proper divisors (27435464).

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

20978776 is a wasteful number, since it uses less digits than its factorization.

20978776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28843 (or 28839 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 46.

The square root of 20978776 is about 4580.2593813015. The cubic root of 20978776 is about 275.7994412183.

The spelling of 20978776 in words is "twenty million, nine hundred seventy-eight thousand, seven hundred seventy-six".