1995243561 has 24 divisors (see below), whose sum is σ = 3039865920. Its totient is φ = 1257594336.

The previous prime is 1995243553. The next prime is 1995243581. The reversal of 1995243561 is 1653425991.

1995243561 is a `hidden beast` number, since 1 + 99 + 524 + 35 + 6 + 1 = 666.

It is not a de Polignac number, because 1995243561 - 2³ = 1995243553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1995243581) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74415 + ... + 97611.

It is an arithmetic number, because the mean of its divisors is an integer number (126661080).

Almost surely, 2^1995243561 is an apocalyptic number.

It is an amenable number.

1995243561 is a deficient number, since it is larger than the sum of its proper divisors (1044622359).

1995243561 is a wasteful number, since it uses less digits than its factorization.

1995243561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23725 (or 23722 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 1995243561 is about 44668.1492900702. The cubic root of 1995243561 is about 1258.9214674637.

The spelling of 1995243561 in words is "one billion, nine hundred ninety-five million, two hundred forty-three thousand, five hundred sixty-one".