661367240680 has 32 divisors (see below), whose sum is σ = 1539389269800. Its totient is φ = 255424589056.

The previous prime is 661367240663. The next prime is 661367240687. The reversal of 661367240680 is 86042763166.

It can be written as a sum of positive squares in 4 ways, for example, as 528584253444 + 132782987236 = 727038^2 + 364394^2 .

It is not an unprimeable number, because it can be changed into a prime (661367240687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285070927 + ... + 285073246.

Almost surely, 2^661367240680 is an apocalyptic number.

It is an amenable number.

661367240680 is an abundant number, since it is smaller than the sum of its proper divisors (878022029120).

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

661367240680 is a wasteful number, since it uses less digits than its factorization.

661367240680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570144213 (or 570144209 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 49.

The spelling of 661367240680 in words is "six hundred sixty-one billion, three hundred sixty-seven million, two hundred forty thousand, six hundred eighty".