670539981 has 4 divisors (see below), whose sum is σ = 894053312. Its totient is φ = 447026652.

The previous prime is 670539977. The next prime is 670539983. The reversal of 670539981 is 189935076.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 670539981 - 2² = 670539977 is a prime.

It is a super-2 number, since 2×670539981² = 899247732238960722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 670539981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (670539983) 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, 111756661 + ... + 111756666.

It is an arithmetic number, because the mean of its divisors is an integer number (223513328).

Almost surely, 2^670539981 is an apocalyptic number.

It is an amenable number.

670539981 is a deficient number, since it is larger than the sum of its proper divisors (223513331).

670539981 is a wasteful number, since it uses less digits than its factorization.

670539981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223513330.

The product of its (nonzero) digits is 408240, while the sum is 48.

The square root of 670539981 is about 25894.7867533216. The cubic root of 670539981 is about 875.2690246522.

The spelling of 670539981 in words is "six hundred seventy million, five hundred thirty-nine thousand, nine hundred eighty-one".