31721146 has 16 divisors (see below), whose sum is σ = 51154560. Its totient is φ = 14705280.

The previous prime is 31721141. The next prime is 31721251. The reversal of 31721146 is 64112713.

It is a super-2 number, since 2×31721146² = 2012462207106632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31721146.

It is not an unprimeable number, because it can be changed into a prime (31721141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7095 + ... + 10666.

It is an arithmetic number, because the mean of its divisors is an integer number (3197160).

Almost surely, 2^31721146 is an apocalyptic number.

31721146 is a deficient number, since it is larger than the sum of its proper divisors (19433414).

31721146 is a wasteful number, since it uses less digits than its factorization.

31721146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17829.

The product of its digits is 1008, while the sum is 25.

The square root of 31721146 is about 5632.1528743457. The cubic root of 31721146 is about 316.5553245987. Note that the first 3 decimals are identical.

Adding to 31721146 its reverse (64112713), we get a palindrome (95833859).

The spelling of 31721146 in words is "thirty-one million, seven hundred twenty-one thousand, one hundred forty-six".