7977561 has 4 divisors (see below), whose sum is σ = 10636752. Its totient is φ = 5318372.

The previous prime is 7977559. The next prime is 7977569. The reversal of 7977561 is 1657797.

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.

It is a cyclic number.

It is not a de Polignac number, because 7977561 - 2¹ = 7977559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7977569) 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, 1329591 + ... + 1329596.

It is an arithmetic number, because the mean of its divisors is an integer number (2659188).

Almost surely, 2^7977561 is an apocalyptic number.

It is an amenable number.

7977561 is a deficient number, since it is larger than the sum of its proper divisors (2659191).

7977561 is a wasteful number, since it uses less digits than its factorization.

7977561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659190.

The product of its digits is 92610, while the sum is 42.

The square root of 7977561 is about 2824.4576470537. The cubic root of 7977561 is about 199.8128332310.

The spelling of 7977561 in words is "seven million, nine hundred seventy-seven thousand, five hundred sixty-one".