646349672 has 8 divisors (see below), whose sum is σ = 1211905650. Its totient is φ = 323174832.

The previous prime is 646349663. The next prime is 646349699. The reversal of 646349672 is 276943646.

It can be written as a sum of positive squares in only one way, i.e., 354418276 + 291931396 = 18826^2 + 17086^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40396847 + ... + 40396862.

Almost surely, 2^646349672 is an apocalyptic number.

It is an amenable number.

646349672 is a deficient number, since it is larger than the sum of its proper divisors (565555978).

646349672 is a wasteful number, since it uses less digits than its factorization.

646349672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80793715 (or 80793711 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 47.

The square root of 646349672 is about 25423.4079540883. The cubic root of 646349672 is about 864.6144926990.

The spelling of 646349672 in words is "six hundred forty-six million, three hundred forty-nine thousand, six hundred seventy-two".