669931 has 2 divisors, whose sum is σ = 669932. Its totient is φ = 669930.

The previous prime is 669923. The next prime is 669937. The reversal of 669931 is 139966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 669931 - 2³ = 669923 is a prime.

It is a super-2 number, since 2×669931² = 897615089522, which contains 22 as substring.

669931 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (669937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334965 + 334966.

It is an arithmetic number, because the mean of its divisors is an integer number (334966).

2⁶⁶⁹⁹³¹ is an apocalyptic number.

669931 is a deficient number, since it is larger than the sum of its proper divisors (1).

669931 is an equidigital number, since it uses as much as digits as its factorization.

669931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 34.

The square root of 669931 is about 818.4931276437. The cubic root of 669931 is about 87.5003972771.

It can be divided in two parts, 669 and 931, that added together give a square (1600 = 40²).

The spelling of 669931 in words is "six hundred sixty-nine thousand, nine hundred thirty-one".