66981934 has 16 divisors (see below), whose sum is σ = 106025760. Its totient is φ = 31672960.

The previous prime is 66981931. The next prime is 66981947. The reversal of 66981934 is 43918966.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66981931) 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, 4087 + ... + 12274.

It is an arithmetic number, because the mean of its divisors is an integer number (6626610).

Almost surely, 2^66981934 is an apocalyptic number.

66981934 is a deficient number, since it is larger than the sum of its proper divisors (39043826).

66981934 is a wasteful number, since it uses less digits than its factorization.

66981934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16475.

The product of its digits is 279936, while the sum is 46.

The square root of 66981934 is about 8184.2491408803. The cubic root of 66981934 is about 406.1183013261.

The spelling of 66981934 in words is "sixty-six million, nine hundred eighty-one thousand, nine hundred thirty-four".