31443021 has 24 divisors (see below), whose sum is σ = 47174400. Its totient is φ = 20160000.

The previous prime is 31442963. The next prime is 31443031. The reversal of 31443021 is 12034413.

It is not a de Polignac number, because 31443021 - 2⁷ = 31442893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31442985 and 31443003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31443031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69805 + ... + 70253.

It is an arithmetic number, because the mean of its divisors is an integer number (1965600).

Almost surely, 2^31443021 is an apocalyptic number.

31443021 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

31443021 is a deficient number, since it is larger than the sum of its proper divisors (15731379).

31443021 is a wasteful number, since it uses less digits than its factorization.

31443021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 31443021 is about 5607.4076898332. The cubic root of 31443021 is about 315.6274417483.

Adding to 31443021 its reverse (12034413), we get a palindrome (43477434).

The spelling of 31443021 in words is "thirty-one million, four hundred forty-three thousand, twenty-one".