1660776257 has 12 divisors (see below), whose sum is σ = 2045566980. Its totient is φ = 1339785216.

The previous prime is 1660776241. The next prime is 1660776259. The reversal of 1660776257 is 7526770661.

It can be written as a sum of positive squares in 2 ways, for example, as 756030016 + 904746241 = 27496^2 + 30079^2 .

It is not a de Polignac number, because 1660776257 - 2⁴ = 1660776241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1660776259) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 996032 + ... + 997697.

It is an arithmetic number, because the mean of its divisors is an integer number (170463915).

Almost surely, 2^1660776257 is an apocalyptic number.

1660776257 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1660776257 is a deficient number, since it is larger than the sum of its proper divisors (384790723).

1660776257 is a wasteful number, since it uses less digits than its factorization.

1660776257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1993760 (or 1993753 counting only the distinct ones).

The product of its (nonzero) digits is 740880, while the sum is 47.

The square root of 1660776257 is about 40752.6227008766. The cubic root of 1660776257 is about 1184.2326821677.

The spelling of 1660776257 in words is "one billion, six hundred sixty million, seven hundred seventy-six thousand, two hundred fifty-seven".