20778872 has 8 divisors (see below), whose sum is σ = 38960400. Its totient is φ = 10389432.

The previous prime is 20778871. The next prime is 20778881. The reversal of 20778872 is 27887702.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1298672 + ... + 1298687.

It is an arithmetic number, because the mean of its divisors is an integer number (4870050).

Almost surely, 2^20778872 is an apocalyptic number.

It is an amenable number.

20778872 is a deficient number, since it is larger than the sum of its proper divisors (18181528).

20778872 is a wasteful number, since it uses less digits than its factorization.

20778872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2597365 (or 2597361 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 41.

The square root of 20778872 is about 4558.3848016595. The cubic root of 20778872 is about 274.9206250256.

The spelling of 20778872 in words is "twenty million, seven hundred seventy-eight thousand, eight hundred seventy-two".