20438856 has 24 divisors (see below), whose sum is σ = 55355430. Its totient is φ = 6812928.

The previous prime is 20438849. The next prime is 20438863. The reversal of 20438856 is 65883402.

It is an interprime number because it is at equal distance from previous prime (20438849) and next prime (20438863).

It can be written as a sum of positive squares in only one way, i.e., 17089956 + 3348900 = 4134^2 + 1830^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20438856.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 141865 + ... + 142008.

Almost surely, 2^20438856 is an apocalyptic number.

It is an amenable number.

20438856 is an abundant number, since it is smaller than the sum of its proper divisors (34916574).

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

20438856 is a wasteful number, since it uses less digits than its factorization.

20438856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283885 (or 283878 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 20438856 is about 4520.9353014614. The cubic root of 20438856 is about 273.4128118401.

It can be divided in two parts, 204 and 38856, that added together give a triangular number (39060 = T₂₇₉).

The spelling of 20438856 in words is "twenty million, four hundred thirty-eight thousand, eight hundred fifty-six".