672641861 has 4 divisors (see below), whose sum is σ = 672694092. Its totient is φ = 672589632.

The previous prime is 672641821. The next prime is 672641869. The reversal of 672641861 is 168146276.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 363093025 + 309548836 = 19055^2 + 17594^2 .

It is a cyclic number.

It is not a de Polignac number, because 672641861 - 2¹⁴ = 672625477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (672641869) 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, 8471 + ... + 37643.

It is an arithmetic number, because the mean of its divisors is an integer number (168173523).

Almost surely, 2^672641861 is an apocalyptic number.

It is an amenable number.

672641861 is a deficient number, since it is larger than the sum of its proper divisors (52231).

672641861 is a wasteful number, since it uses less digits than its factorization.

672641861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52230.

The product of its digits is 96768, while the sum is 41.

The square root of 672641861 is about 25935.3400016271. The cubic root of 672641861 is about 876.1826125034.

The spelling of 672641861 in words is "six hundred seventy-two million, six hundred forty-one thousand, eight hundred sixty-one".