661727377 has 4 divisors (see below), whose sum is σ = 669700080. Its totient is φ = 653754676.

The previous prime is 661727369. The next prime is 661727401. The reversal of 661727377 is 773727166.

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 a cyclic number.

It is not a de Polignac number, because 661727377 - 2³ = 661727369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661727477) 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, 3986227 + ... + 3986392.

It is an arithmetic number, because the mean of its divisors is an integer number (167425020).

Almost surely, 2^661727377 is an apocalyptic number.

It is an amenable number.

661727377 is a deficient number, since it is larger than the sum of its proper divisors (7972703).

661727377 is an equidigital number, since it uses as much as digits as its factorization.

661727377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7972702.

The product of its digits is 518616, while the sum is 46.

The square root of 661727377 is about 25724.0622180868. The cubic root of 661727377 is about 871.4176811209.

The spelling of 661727377 in words is "six hundred sixty-one million, seven hundred twenty-seven thousand, three hundred seventy-seven".