31220242 has 4 divisors (see below), whose sum is σ = 46830366. Its totient is φ = 15610120.

The previous prime is 31220239. The next prime is 31220243. The reversal of 31220242 is 24202213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 23707161 + 7513081 = 4869^2 + 2741^2 .

It is not an unprimeable number, because it can be changed into a prime (31220243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7805059 + ... + 7805062.

Almost surely, 2^31220242 is an apocalyptic number.

31220242 is a deficient number, since it is larger than the sum of its proper divisors (15610124).

31220242 is a wasteful number, since it uses less digits than its factorization.

31220242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15610123.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 31220242 is about 5587.5076733728. The cubic root of 31220242 is about 314.8802501063.

Adding to 31220242 its reverse (24202213), we get a palindrome (55422455).

The spelling of 31220242 in words is "thirty-one million, two hundred twenty thousand, two hundred forty-two".