661260590021 has 8 divisors (see below), whose sum is σ = 663007887360. Its totient is φ = 659513536528.

The previous prime is 661260589999. The next prime is 661260590033. The reversal of 661260590021 is 120095062166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661260590021 - 2³⁴ = 644080720837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661260560021) 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, 6220700 + ... + 6326106.

It is an arithmetic number, because the mean of its divisors is an integer number (82875985920).

Almost surely, 2^661260590021 is an apocalyptic number.

It is an amenable number.

661260590021 is a deficient number, since it is larger than the sum of its proper divisors (1747297339).

661260590021 is a wasteful number, since it uses less digits than its factorization.

661260590021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121923.

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 661260590021 in words is "six hundred sixty-one billion, two hundred sixty million, five hundred ninety thousand, twenty-one".