1565656541 has 4 divisors (see below), whose sum is σ = 1566803232. Its totient is φ = 1564509852.

The previous prime is 1565656511. The next prime is 1565656549. The reversal of 1565656541 is 1456565651.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1456565651 = 271 ⋅5374781.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1565656541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1565656492 and 1565656501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565656549) 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, 571295 + ... + 574028.

It is an arithmetic number, because the mean of its divisors is an integer number (391700808).

Almost surely, 2^1565656541 is an apocalyptic number.

It is an amenable number.

1565656541 is a deficient number, since it is larger than the sum of its proper divisors (1146691).

1565656541 is a wasteful number, since it uses less digits than its factorization.

1565656541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1146690.

The product of its digits is 540000, while the sum is 44.

The square root of 1565656541 is about 39568.3780435842. The cubic root of 1565656541 is about 1161.1780889554.

The spelling of 1565656541 in words is "one billion, five hundred sixty-five million, six hundred fifty-six thousand, five hundred forty-one".