31221970 has 16 divisors (see below), whose sum is σ = 60522840. Its totient is φ = 11528064.

The previous prime is 31221961. The next prime is 31221977. The reversal of 31221970 is 7912213.

It can be written as a sum of positive squares in 4 ways, for example, as 27384289 + 3837681 = 5233^2 + 1959^2 .

It is a super-2 number, since 2×31221970² = 1949622821361800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31221977) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 119955 + ... + 120214.

Almost surely, 2^31221970 is an apocalyptic number.

31221970 is a deficient number, since it is larger than the sum of its proper divisors (29300870).

31221970 is a wasteful number, since it uses less digits than its factorization.

31221970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240189.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 31221970 is about 5587.6623018933. The cubic root of 31221970 is about 314.8860594039.

The spelling of 31221970 in words is "thirty-one million, two hundred twenty-one thousand, nine hundred seventy".