661657029 has 8 divisors (see below), whose sum is σ = 962410272. Its totient is φ = 401004240.

The previous prime is 661657021. The next prime is 661657049. The reversal of 661657029 is 920756166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661657029 - 2³ = 661657021 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661657021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10025074 + ... + 10025139.

It is an arithmetic number, because the mean of its divisors is an integer number (120301284).

Almost surely, 2^661657029 is an apocalyptic number.

It is an amenable number.

661657029 is a deficient number, since it is larger than the sum of its proper divisors (300753243).

661657029 is a wasteful number, since it uses less digits than its factorization.

661657029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20050227.

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 661657029 is about 25722.6948238321. The cubic root of 661657029 is about 871.3867999929.

The spelling of 661657029 in words is "six hundred sixty-one million, six hundred fifty-seven thousand, twenty-nine".