661377461250 has 80 divisors (see below), whose sum is σ = 1803179622816. Its totient is φ = 160333920000.

The previous prime is 661377461177. The next prime is 661377461257. The reversal of 661377461250 is 52164773166.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 661377461250.

It is not an unprimeable number, because it can be changed into a prime (661377461257) 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 39 ways as a sum of consecutive naturals, for example, 7975447 + ... + 8057946.

Almost surely, 2^661377461250 is an apocalyptic number.

661377461250 is an abundant number, since it is smaller than the sum of its proper divisors (1141802161566).

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

661377461250 is a wasteful number, since it uses less digits than its factorization.

661377461250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16033429 (or 16033414 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 48.

The spelling of 661377461250 in words is "six hundred sixty-one billion, three hundred seventy-seven million, four hundred sixty-one thousand, two hundred fifty".