661044462511550 has 24 divisors (see below), whose sum is σ = 1324122907985976. Its totient is φ = 244077955388640.

The previous prime is 661044462511529. The next prime is 661044462511553. The reversal of 661044462511550 is 55115264440166.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661044462511553) 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, 508495739744 + ... + 508495741043.

It is an arithmetic number, because the mean of its divisors is an integer number (55171787832749).

Almost surely, 2^{661044462511550} is an apocalyptic number.

661044462511550 is an abundant number, since it is smaller than the sum of its proper divisors (663078445474426).

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

661044462511550 is a wasteful number, since it uses less digits than its factorization.

661044462511550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016991480812 (or 1016991480807 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 50.

The spelling of 661044462511550 in words is "six hundred sixty-one trillion, forty-four billion, four hundred sixty-two million, five hundred eleven thousand, five hundred fifty".