31626742381 has 4 divisors (see below), whose sum is σ = 34059568732. Its totient is φ = 29193916032.

The previous prime is 31626742361. The next prime is 31626742393. The reversal of 31626742381 is 18324762613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18324762613 = 359 ⋅51043907.

It can be written as a sum of positive squares in 2 ways, for example, as 1815612100 + 29811130281 = 42610^2 + 172659^2 .

It is a cyclic number.

It is not a de Polignac number, because 31626742381 - 2⁷ = 31626742253 is a prime.

It is a super-2 number, since 2×31626742381² (a number of 22 digits) 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 (31626742321) 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, 1216413156 + ... + 1216413181.

It is an arithmetic number, because the mean of its divisors is an integer number (8514892183).

Almost surely, 2^31626742381 is an apocalyptic number.

It is an amenable number.

31626742381 is a deficient number, since it is larger than the sum of its proper divisors (2432826351).

31626742381 is a wasteful number, since it uses less digits than its factorization.

31626742381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2432826350.

The product of its digits is 290304, while the sum is 43.

The spelling of 31626742381 in words is "thirty-one billion, six hundred twenty-six million, seven hundred forty-two thousand, three hundred eighty-one".