20779680 has 48 divisors (see below), whose sum is σ = 65457504. Its totient is φ = 5541120.

The previous prime is 20779609. The next prime is 20779697. The reversal of 20779680 is 8697702.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21166 + ... + 22125.

It is an arithmetic number, because the mean of its divisors is an integer number (1363698).

Almost surely, 2^20779680 is an apocalyptic number.

20779680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20779680 is an abundant number, since it is smaller than the sum of its proper divisors (44677824).

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

20779680 is a wasteful number, since it uses less digits than its factorization.

20779680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43309 (or 43301 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 39.

The square root of 20779680 is about 4558.4734286820. The cubic root of 20779680 is about 274.9241884687.

The spelling of 20779680 in words is "twenty million, seven hundred seventy-nine thousand, six hundred eighty".