31745561 has 4 divisors (see below), whose sum is σ = 33416400. Its totient is φ = 30074724.

The previous prime is 31745533. The next prime is 31745621. The reversal of 31745561 is 16554713.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31745561 - 2²² = 27551257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31745501) 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, 835391 + ... + 835428.

It is an arithmetic number, because the mean of its divisors is an integer number (8354100).

Almost surely, 2^31745561 is an apocalyptic number.

It is an amenable number.

31745561 is a deficient number, since it is larger than the sum of its proper divisors (1670839).

31745561 is a wasteful number, since it uses less digits than its factorization.

31745561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1670838.

The product of its digits is 12600, while the sum is 32.

The square root of 31745561 is about 5634.3199234690. The cubic root of 31745561 is about 316.6365187673.

The spelling of 31745561 in words is "thirty-one million, seven hundred forty-five thousand, five hundred sixty-one".