661670023 has 4 divisors (see below), whose sum is σ = 756194320. Its totient is φ = 567145728.

The previous prime is 661669999. The next prime is 661670033. The reversal of 661670023 is 320076166.

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

It is a cyclic number.

It is not a de Polignac number, because 661670023 - 2⁵ = 661669991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661670033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47262138 + ... + 47262151.

It is an arithmetic number, because the mean of its divisors is an integer number (189048580).

Almost surely, 2^661670023 is an apocalyptic number.

661670023 is a deficient number, since it is larger than the sum of its proper divisors (94524297).

661670023 is an equidigital number, since it uses as much as digits as its factorization.

661670023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94524296.

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 661670023 is about 25722.9474011047. The cubic root of 661670023 is about 871.3925042200.

The spelling of 661670023 in words is "six hundred sixty-one million, six hundred seventy thousand, twenty-three".