20139866 has 16 divisors (see below), whose sum is σ = 32187456. Its totient is φ = 9418176.

The previous prime is 20139857. The next prime is 20139869. The reversal of 20139866 is 66893102.

It is a super-2 number, since 2×20139866² = 811228404995912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20139869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3905 + ... + 7451.

It is an arithmetic number, because the mean of its divisors is an integer number (2011716).

Almost surely, 2^20139866 is an apocalyptic number.

20139866 is a deficient number, since it is larger than the sum of its proper divisors (12047590).

20139866 is a wasteful number, since it uses less digits than its factorization.

20139866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3733.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 20139866 is about 4487.7462049452. The cubic root of 20139866 is about 272.0730502323.

The spelling of 20139866 in words is "twenty million, one hundred thirty-nine thousand, eight hundred sixty-six".