31881901 has 8 divisors (see below), whose sum is σ = 32849784. Its totient is φ = 30919680.

The previous prime is 31881853. The next prime is 31881907. The reversal of 31881901 is 10918813.

It can be written as a sum of positive squares in 4 ways, for example, as 3515625 + 28366276 = 1875^2 + 5326^2 .

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 31881901 - 2²³ = 23493293 is a prime.

It is a super-2 number, since 2×31881901² = 2032911222747602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31881907) 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, 11841 + ... + 14281.

It is an arithmetic number, because the mean of its divisors is an integer number (4106223).

Almost surely, 2^31881901 is an apocalyptic number.

It is an amenable number.

31881901 is a deficient number, since it is larger than the sum of its proper divisors (967883).

31881901 is a wasteful number, since it uses less digits than its factorization.

31881901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2831.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 31881901 is about 5646.4060250747. The cubic root of 31881901 is about 317.0891654423.

The spelling of 31881901 in words is "thirty-one million, eight hundred eighty-one thousand, nine hundred one".