4031561861 has 4 divisors (see below), whose sum is σ = 4032551424. Its totient is φ = 4030572300.

The previous prime is 4031561843. The next prime is 4031561867. The reversal of 4031561861 is 1681651304.

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.

It is a cyclic number.

It is not a de Polignac number, because 4031561861 - 2¹⁸ = 4031299717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4031561867) 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, 488645 + ... + 496826.

It is an arithmetic number, because the mean of its divisors is an integer number (1008137856).

Almost surely, 2^4031561861 is an apocalyptic number.

It is an amenable number.

4031561861 is a deficient number, since it is larger than the sum of its proper divisors (989563).

4031561861 is an equidigital number, since it uses as much as digits as its factorization.

4031561861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989562.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 4031561861 is about 63494.5813514823. The cubic root of 4031561861 is about 1591.5652296103.

The spelling of 4031561861 in words is "four billion, thirty-one million, five hundred sixty-one thousand, eight hundred sixty-one".