66156939 has 16 divisors (see below), whose sum is σ = 99475840. Its totient is φ = 43445160.

The previous prime is 66156929. The next prime is 66156941. The reversal of 66156939 is 93965166.

It is not a de Polignac number, because 66156939 - 2⁹ = 66156427 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66156894 and 66156903.

It is not an unprimeable number, because it can be changed into a prime (66156929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16477 + ... + 20094.

It is an arithmetic number, because the mean of its divisors is an integer number (6217240).

Almost surely, 2^66156939 is an apocalyptic number.

66156939 is a deficient number, since it is larger than the sum of its proper divisors (33318901).

66156939 is a wasteful number, since it uses less digits than its factorization.

66156939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36647 (or 36641 counting only the distinct ones).

The product of its digits is 262440, while the sum is 45.

The square root of 66156939 is about 8133.6915973007. The cubic root of 66156939 is about 404.4440657632. Note that the first 3 decimals are identical.

It can be divided in two parts, 661 and 56939, that added together give a square (57600 = 240²).

The spelling of 66156939 in words is "sixty-six million, one hundred fifty-six thousand, nine hundred thirty-nine".