661501076 has 12 divisors (see below), whose sum is σ = 1225722708. Its totient is φ = 311294592.

The previous prime is 661501069. The next prime is 661501081. The reversal of 661501076 is 670105166.

It can be written as a sum of positive squares in 2 ways, for example, as 361380100 + 300120976 = 19010^2 + 17324^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4863911 + ... + 4864046.

It is an arithmetic number, because the mean of its divisors is an integer number (102143559).

Almost surely, 2^661501076 is an apocalyptic number.

It is an amenable number.

661501076 is a deficient number, since it is larger than the sum of its proper divisors (564221632).

661501076 is a wasteful number, since it uses less digits than its factorization.

661501076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9727978 (or 9727976 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 661501076 is about 25719.6632170797. The cubic root of 661501076 is about 871.3183324646.

The spelling of 661501076 in words is "six hundred sixty-one million, five hundred one thousand, seventy-six".