1631881 has 8 divisors (see below), whose sum is σ = 1758240. Its totient is φ = 1508928.

The previous prime is 1631879. The next prime is 1631897. The reversal of 1631881 is 1881361.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1631881 - 2¹ = 1631879 is a prime.

It is a super-2 number, since 2×1631881² = 5326071196322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1631821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190 + ... + 1816.

It is an arithmetic number, because the mean of its divisors is an integer number (219780).

2^1631881 is an apocalyptic number.

It is an amenable number.

1631881 is a deficient number, since it is larger than the sum of its proper divisors (126359).

1631881 is a wasteful number, since it uses less digits than its factorization.

1631881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1703.

The product of its digits is 1152, while the sum is 28.

The square root of 1631881 is about 1277.4509775330. The cubic root of 1631881 is about 117.7324446461.

Subtracting from 1631881 its product of digits (1152), we obtain a square (1630729 = 1277²).

It can be divided in two parts, 163 and 1881, that multiplied together give a palindrome (306603).

The spelling of 1631881 in words is "one million, six hundred thirty-one thousand, eight hundred eighty-one".