1565477961 has 4 divisors (see below), whose sum is σ = 2087303952. Its totient is φ = 1043651972.

The previous prime is 1565477941. The next prime is 1565478037. The reversal of 1565477961 is 1697745651.

It is a happy number.

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 1565477961 - 2¹⁴ = 1565461577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1565477941) 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, 260912991 + ... + 260912996.

It is an arithmetic number, because the mean of its divisors is an integer number (521825988).

Almost surely, 2^1565477961 is an apocalyptic number.

It is an amenable number.

1565477961 is a deficient number, since it is larger than the sum of its proper divisors (521825991).

1565477961 is an equidigital number, since it uses as much as digits as its factorization.

1565477961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521825990.

The product of its digits is 1587600, while the sum is 51.

The square root of 1565477961 is about 39566.1213792810. The cubic root of 1565477961 is about 1161.1339389855.

The spelling of 1565477961 in words is "one billion, five hundred sixty-five million, four hundred seventy-seven thousand, nine hundred sixty-one".