6661890513877 has 8 divisors (see below), whose sum is σ = 7056332415000. Its totient is φ = 6267733722624.

The previous prime is 6661890513871. The next prime is 6661890513923. The reversal of 6661890513877 is 7783150981666.

It can be written as a sum of positive squares in 4 ways, for example, as 16353038641 + 6645537475236 = 127879^2 + 2577894^2 .

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 6661890513877 - 2¹⁹ = 6661889989589 is a prime.

It is a super-2 number, since 2×6661890513877² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661890513871) 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, 71229352 + ... + 71322817.

It is an arithmetic number, because the mean of its divisors is an integer number (882041551875).

Almost surely, 2^{6661890513877} is an apocalyptic number.

It is an amenable number.

6661890513877 is a deficient number, since it is larger than the sum of its proper divisors (394441901123).

6661890513877 is a wasteful number, since it uses less digits than its factorization.

6661890513877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142554935.

The product of its (nonzero) digits is 91445760, while the sum is 67.

The spelling of 6661890513877 in words is "six trillion, six hundred sixty-one billion, eight hundred ninety million, five hundred thirteen thousand, eight hundred seventy-seven".