31285442 has 4 divisors (see below), whose sum is σ = 46928166. Its totient is φ = 15642720.

The previous prime is 31285421. The next prime is 31285447. The reversal of 31285442 is 24458213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24458213 = 13 ⋅1881401.

It can be written as a sum of positive squares in only one way, i.e., 21242881 + 10042561 = 4609^2 + 3169^2 .

It is a super-2 number, since 2×31285442² = 1957557762270728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31285447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7821359 + ... + 7821362.

Almost surely, 2^31285442 is an apocalyptic number.

31285442 is a deficient number, since it is larger than the sum of its proper divisors (15642724).

31285442 is a wasteful number, since it uses less digits than its factorization.

31285442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15642723.

The product of its digits is 7680, while the sum is 29.

The square root of 31285442 is about 5593.3390742918. The cubic root of 31285442 is about 315.0992951433.

The spelling of 31285442 in words is "thirty-one million, two hundred eighty-five thousand, four hundred forty-two".