1561189231 has 16 divisors (see below), whose sum is σ = 1824409600. Its totient is φ = 1308348288.

The previous prime is 1561189229. The next prime is 1561189243. The reversal of 1561189231 is 1329811651.

It is a cyclic number.

It is not a de Polignac number, because 1561189231 - 2¹ = 1561189229 is a prime.

It is a super-2 number, since 2×1561189231² = 4874623629980742722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561189291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43255 + ... + 70663.

It is an arithmetic number, because the mean of its divisors is an integer number (114025600).

Almost surely, 2^1561189231 is an apocalyptic number.

1561189231 is a deficient number, since it is larger than the sum of its proper divisors (263220369).

1561189231 is a wasteful number, since it uses less digits than its factorization.

1561189231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27598.

The product of its digits is 12960, while the sum is 37.

The square root of 1561189231 is about 39511.8872113191. The cubic root of 1561189231 is about 1160.0726349187.

The spelling of 1561189231 in words is "one billion, five hundred sixty-one million, one hundred eighty-nine thousand, two hundred thirty-one".