12977561 has 4 divisors (see below), whose sum is σ = 13396224. Its totient is φ = 12558900.

The previous prime is 12977539. The next prime is 12977597. The reversal of 12977561 is 16577921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16577921 = 1579 ⋅10499.

It is a cyclic number.

It is not a de Polignac number, because 12977561 - 2¹⁴ = 12961177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12977501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209285 + ... + 209346.

It is an arithmetic number, because the mean of its divisors is an integer number (3349056).

Almost surely, 2^12977561 is an apocalyptic number.

It is an amenable number.

12977561 is a deficient number, since it is larger than the sum of its proper divisors (418663).

12977561 is an equidigital number, since it uses as much as digits as its factorization.

12977561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418662.

The product of its digits is 26460, while the sum is 38.

The square root of 12977561 is about 3602.4382021070. The cubic root of 12977561 is about 234.9981047078.

The spelling of 12977561 in words is "twelve million, nine hundred seventy-seven thousand, five hundred sixty-one".