1561617432 has 24 divisors (see below), whose sum is σ = 4229380740. Its totient is φ = 520539120.

The previous prime is 1561617427. The next prime is 1561617437. The reversal of 1561617432 is 2347161651.

1561617432 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 617 + 4 + 32 = 666.

It is an interprime number because it is at equal distance from previous prime (1561617427) and next prime (1561617437).

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561617437) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10844494 + ... + 10844637.

Almost surely, 2^1561617432 is an apocalyptic number.

1561617432 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1561617432 is an abundant number, since it is smaller than the sum of its proper divisors (2667763308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561617432 is a wasteful number, since it uses less digits than its factorization.

1561617432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21689143 (or 21689136 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 1561617432 is about 39517.3054749435. The cubic root of 1561617432 is about 1160.1786863065.

The spelling of 1561617432 in words is "one billion, five hundred sixty-one million, six hundred seventeen thousand, four hundred thirty-two".