661601151 has 12 divisors (see below), whose sum is σ = 956166120. Its totient is φ = 440827440.

The previous prime is 661601131. The next prime is 661601159. The reversal of 661601151 is 151106166.

661601151 is a `hidden beast` number, since 6 + 6 + 1 + 601 + 1 + 51 = 666.

It is not a de Polignac number, because 661601151 - 2⁵ = 661601119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661601159) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1656 + ... + 36413.

It is an arithmetic number, because the mean of its divisors is an integer number (79680510).

Almost surely, 2^661601151 is an apocalyptic number.

661601151 is a deficient number, since it is larger than the sum of its proper divisors (294564969).

661601151 is a wasteful number, since it uses less digits than its factorization.

661601151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40006 (or 40003 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 661601151 is about 25721.6086394300. The cubic root of 661601151 is about 871.3622692968.

The spelling of 661601151 in words is "six hundred sixty-one million, six hundred one thousand, one hundred fifty-one".