661542504364 has 48 divisors (see below), whose sum is σ = 1350659968000. Its totient is φ = 283397840208.

The previous prime is 661542504361. The next prime is 661542504367. The reversal of 661542504364 is 463405245166.

It is an interprime number because it is at equal distance from previous prime (661542504361) and next prime (661542504367).

It is not an unprimeable number, because it can be changed into a prime (661542504361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3168307 + ... + 3370645.

Almost surely, 2^661542504364 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661542504364, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (675329984000).

661542504364 is an abundant number, since it is smaller than the sum of its proper divisors (689117463636).

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

661542504364 is a wasteful number, since it uses less digits than its factorization.

661542504364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204747 (or 204731 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 46.

The spelling of 661542504364 in words is "six hundred sixty-one billion, five hundred forty-two million, five hundred four thousand, three hundred sixty-four".