20856554 has 4 divisors (see below), whose sum is σ = 31284834. Its totient is φ = 10428276.

The previous prime is 20856551. The next prime is 20856599. The reversal of 20856554 is 45565802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15816529 + 5040025 = 3977^2 + 2245^2 .

It is not an unprimeable number, because it can be changed into a prime (20856551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5214137 + ... + 5214140.

Almost surely, 2^20856554 is an apocalyptic number.

20856554 is a deficient number, since it is larger than the sum of its proper divisors (10428280).

20856554 is a wasteful number, since it uses less digits than its factorization.

20856554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10428279.

The product of its (nonzero) digits is 48000, while the sum is 35.

The square root of 20856554 is about 4566.8976340619. The cubic root of 20856554 is about 275.2627967189.

The spelling of 20856554 in words is "twenty million, eight hundred fifty-six thousand, five hundred fifty-four".