1660977086521 has 27 divisors (see below), whose sum is σ = 1816307136111. Its totient is φ = 1518647095728.

The previous prime is 1660977086507. The next prime is 1660977086539. The reversal of 1660977086521 is 1256807790661.

The square root of 1660977086521 is 1288789.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 870976094121 + 790000992400 = 933261^2 + 888820^2 .

It is not a de Polignac number, because 1660977086521 - 2³¹ = 1658829602873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1660977086591) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 710121570 + ... + 710123908.

Almost surely, 2^{1660977086521} is an apocalyptic number.

1660977086521 is the 1288789-th square number.

1660977086521 is the 644395-th centered octagonal number.

It is an amenable number.

1660977086521 is a deficient number, since it is larger than the sum of its proper divisors (155330049590).

1660977086521 is an frugal number, since it uses more digits than its factorization.

1660977086521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4774 (or 2387 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 58.

The spelling of 1660977086521 in words is "one trillion, six hundred sixty billion, nine hundred seventy-seven million, eighty-six thousand, five hundred twenty-one".