1661406431 has 16 divisors (see below), whose sum is σ = 1730365440. Its totient is φ = 1594032480.

The previous prime is 1661406427. The next prime is 1661406443. The reversal of 1661406431 is 1346041661.

It is not a de Polignac number, because 1661406431 - 2² = 1661406427 is a prime.

It is a super-2 number, since 2×1661406431² = 5520542657936315522, 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 (1661406401) 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, 1051400 + ... + 1052978.

It is an arithmetic number, because the mean of its divisors is an integer number (108147840).

Almost surely, 2^1661406431 is an apocalyptic number.

1661406431 is a deficient number, since it is larger than the sum of its proper divisors (68959009).

1661406431 is a wasteful number, since it uses less digits than its factorization.

1661406431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2054.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 1661406431 is about 40760.3536662772. The cubic root of 1661406431 is about 1184.3824471291.

The spelling of 1661406431 in words is "one billion, six hundred sixty-one million, four hundred six thousand, four hundred thirty-one".