661335061051 has 64 divisors (see below), whose sum is σ = 790629580800. Its totient is φ = 552811422240.

The previous prime is 661335061043. The next prime is 661335061067. The reversal of 661335061051 is 150160533166.

It is not a de Polignac number, because 661335061051 - 2³ = 661335061043 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661335061051.

It is not an unprimeable number, because it can be changed into a prime (661335061001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1726723206 + ... + 1726723588.

It is an arithmetic number, because the mean of its divisors is an integer number (12353587200).

Almost surely, 2^661335061051 is an apocalyptic number.

661335061051 is a deficient number, since it is larger than the sum of its proper divisors (129294519749).

661335061051 is a wasteful number, since it uses less digits than its factorization.

661335061051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029 (or 1015 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 37.

The spelling of 661335061051 in words is "six hundred sixty-one billion, three hundred thirty-five million, sixty-one thousand, fifty-one".