1656131431 has 4 divisors (see below), whose sum is σ = 1677095200. Its totient is φ = 1635167664.

The previous prime is 1656131429. The next prime is 1656131443. The reversal of 1656131431 is 1341316561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1656131431 - 2¹ = 1656131429 is a prime.

It is a super-2 number, since 2×1656131431² = 5485542633492215522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1656131393 and 1656131402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656131471) 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, 10481766 + ... + 10481923.

It is an arithmetic number, because the mean of its divisors is an integer number (419273800).

Almost surely, 2^1656131431 is an apocalyptic number.

1656131431 is a deficient number, since it is larger than the sum of its proper divisors (20963769).

1656131431 is an equidigital number, since it uses as much as digits as its factorization.

1656131431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20963768.

The product of its digits is 6480, while the sum is 31.

The square root of 1656131431 is about 40695.5947370228. The cubic root of 1656131431 is about 1183.1276385355.

Adding to 1656131431 its reverse (1341316561), we get a palindrome (2997447992).

The spelling of 1656131431 in words is "one billion, six hundred fifty-six million, one hundred thirty-one thousand, four hundred thirty-one".