672640729 has 4 divisors (see below), whose sum is σ = 680198580. Its totient is φ = 665082880.

The previous prime is 672640721. The next prime is 672640733. The reversal of 672640729 is 927046276.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53626329 + 619014400 = 7323^2 + 24880^2 .

It is a cyclic number.

It is not a de Polignac number, because 672640729 - 2³ = 672640721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (672640721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3778792 + ... + 3778969.

It is an arithmetic number, because the mean of its divisors is an integer number (170049645).

Almost surely, 2^672640729 is an apocalyptic number.

It is an amenable number.

672640729 is a deficient number, since it is larger than the sum of its proper divisors (7557851).

672640729 is an equidigital number, since it uses as much as digits as its factorization.

672640729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7557850.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 672640729 is about 25935.3181781138. The cubic root of 672640729 is about 876.1821209891.

The spelling of 672640729 in words is "six hundred seventy-two million, six hundred forty thousand, seven hundred twenty-nine".