31220145 has 48 divisors (see below), whose sum is σ = 60091200. Its totient is φ = 14866560.

The previous prime is 31220093. The next prime is 31220159. The reversal of 31220145 is 54102213.

It is not a de Polignac number, because 31220145 - 2⁶ = 31220081 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28671 + ... + 29739.

It is an arithmetic number, because the mean of its divisors is an integer number (1251900).

Almost surely, 2^31220145 is an apocalyptic number.

It is an amenable number.

31220145 is a deficient number, since it is larger than the sum of its proper divisors (28871055).

31220145 is a wasteful number, since it uses less digits than its factorization.

31220145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150 (or 1147 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 31220145 is about 5587.4989932885. The cubic root of 31220145 is about 314.8799239993.

Adding to 31220145 its reverse (54102213), we get a palindrome (85322358).

The spelling of 31220145 in words is "thirty-one million, two hundred twenty thousand, one hundred forty-five".