661886061424 has 40 divisors (see below), whose sum is σ = 1542741952640. Its totient is φ = 268735693248.

The previous prime is 661886061391. The next prime is 661886061457. The reversal of 661886061424 is 424160688166.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (661886061391) and next prime (661886061457).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155516214 + ... + 155520469.

It is an arithmetic number, because the mean of its divisors is an integer number (38568548816).

Almost surely, 2^661886061424 is an apocalyptic number.

It is an amenable number.

661886061424 is an abundant number, since it is smaller than the sum of its proper divisors (880855891216).

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

661886061424 is a wasteful number, since it uses less digits than its factorization.

661886061424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311036717 (or 311036711 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 52.

The spelling of 661886061424 in words is "six hundred sixty-one billion, eight hundred eighty-six million, sixty-one thousand, four hundred twenty-four".