20856874 has 4 divisors (see below), whose sum is σ = 31285314. Its totient is φ = 10428436.

The previous prime is 20856839. The next prime is 20856877. The reversal of 20856874 is 47865802.

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., 19053225 + 1803649 = 4365^2 + 1343^2 .

It is not an unprimeable number, because it can be changed into a prime (20856877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5214217 + ... + 5214220.

Almost surely, 2^20856874 is an apocalyptic number.

20856874 is a deficient number, since it is larger than the sum of its proper divisors (10428440).

20856874 is a wasteful number, since it uses less digits than its factorization.

20856874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10428439.

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 20856874 is about 4566.9326686519. The cubic root of 20856874 is about 275.2642044881.

The spelling of 20856874 in words is "twenty million, eight hundred fifty-six thousand, eight hundred seventy-four".