660138477 has 4 divisors (see below), whose sum is σ = 880184640. Its totient is φ = 440092316.

The previous prime is 660138469. The next prime is 660138481. The reversal of 660138477 is 774831066.

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 660138477 - 2³ = 660138469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660138467) 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, 110023077 + ... + 110023082.

It is an arithmetic number, because the mean of its divisors is an integer number (220046160).

Almost surely, 2^660138477 is an apocalyptic number.

It is an amenable number.

660138477 is a deficient number, since it is larger than the sum of its proper divisors (220046163).

660138477 is a wasteful number, since it uses less digits than its factorization.

660138477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220046162.

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 660138477 is about 25693.1601209349. The cubic root of 660138477 is about 870.7196568867.

The spelling of 660138477 in words is "six hundred sixty million, one hundred thirty-eight thousand, four hundred seventy-seven".