1561641732 has 36 divisors (see below), whose sum is σ = 4511410176. Its totient is φ = 446183280.

The previous prime is 1561641727. The next prime is 1561641737. The reversal of 1561641732 is 2371461651.

1561641732 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 641 + 7 + 3 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (1561641727) and next prime (1561641737).

It is a tau number, because it is divible by the number of its divisors (36).

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

It is not an unprimeable number, because it can be changed into a prime (1561641737) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3098244 + ... + 3098747.

Almost surely, 2^1561641732 is an apocalyptic number.

1561641732 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1561641732 is an abundant number, since it is smaller than the sum of its proper divisors (2949768444).

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

1561641732 is a wasteful number, since it uses less digits than its factorization.

1561641732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6197008 (or 6197003 counting only the distinct ones).

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

The square root of 1561641732 is about 39517.6129339817. The cubic root of 1561641732 is about 1160.1847040407.

The spelling of 1561641732 in words is "one billion, five hundred sixty-one million, six hundred forty-one thousand, seven hundred thirty-two".