661916154 has 16 divisors (see below), whose sum is σ = 1366536960. Its totient is φ = 213521280.

The previous prime is 661916147. The next prime is 661916161. The reversal of 661916154 is 451619166.

It is an interprime number because it is at equal distance from previous prime (661916147) and next prime (661916161).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1779159 + ... + 1779530.

It is an arithmetic number, because the mean of its divisors is an integer number (85408560).

Almost surely, 2^661916154 is an apocalyptic number.

661916154 is an abundant number, since it is smaller than the sum of its proper divisors (704620806).

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

661916154 is a wasteful number, since it uses less digits than its factorization.

661916154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3558725.

The product of its digits is 38880, while the sum is 39.

The square root of 661916154 is about 25727.7312252752. The cubic root of 661916154 is about 871.5005389969.

The spelling of 661916154 in words is "six hundred sixty-one million, nine hundred sixteen thousand, one hundred fifty-four".