20788551 has 12 divisors (see below), whose sum is σ = 34317712. Its totient is φ = 11879136.

The previous prime is 20788513. The next prime is 20788553. The reversal of 20788551 is 15588702.

20788551 is a `hidden beast` number, since 20 + 7 + 88 + 551 = 666.

It is not a de Polignac number, because 20788551 - 2⁹ = 20788039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20788553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 164926 + ... + 165051.

Almost surely, 2^20788551 is an apocalyptic number.

20788551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20788551 is a deficient number, since it is larger than the sum of its proper divisors (13529161).

20788551 is a wasteful number, since it uses less digits than its factorization.

20788551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329990 (or 329987 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 20788551 is about 4559.4463479681. The cubic root of 20788551 is about 274.9633052967.

It can be divided in two parts, 207885 and 51, that added together give a square (207936 = 456²).

The spelling of 20788551 in words is "twenty million, seven hundred eighty-eight thousand, five hundred fifty-one".