661379898 has 16 divisors (see below), whose sum is σ = 1347718176. Its totient is φ = 216300240.

The previous prime is 661379893. The next prime is 661379909. The reversal of 661379898 is 898973166.

It is not an unprimeable number, because it can be changed into a prime (661379893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1039588 + ... + 1040223.

It is an arithmetic number, because the mean of its divisors is an integer number (84232386).

Almost surely, 2^661379898 is an apocalyptic number.

661379898 is an abundant number, since it is smaller than the sum of its proper divisors (686338278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661379898 is a wasteful number, since it uses less digits than its factorization.

661379898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2079869.

The product of its digits is 3919104, while the sum is 57.

The square root of 661379898 is about 25717.3073629414. The cubic root of 661379898 is about 871.2651246596.

The spelling of 661379898 in words is "six hundred sixty-one million, three hundred seventy-nine thousand, eight hundred ninety-eight".