31403021221 has 24 divisors (see below), whose sum is σ = 37444142232. Its totient is φ = 26159654400.

The previous prime is 31403021201. The next prime is 31403021233. The reversal of 31403021221 is 12212030413.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3259268100 + 28143753121 = 57090^2 + 167761^2 .

It is not a de Polignac number, because 31403021221 - 2²¹ = 31400924069 is a prime.

It is a super-2 number, since 2×31403021221² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31403021201) 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, 142641 + ... + 288361.

It is an arithmetic number, because the mean of its divisors is an integer number (1560172593).

Almost surely, 2^31403021221 is an apocalyptic number.

It is an amenable number.

31403021221 is a deficient number, since it is larger than the sum of its proper divisors (6041121011).

31403021221 is a wasteful number, since it uses less digits than its factorization.

31403021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145893 (or 145882 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31403021221 its reverse (12212030413), we get a palindrome (43615051634).

The spelling of 31403021221 in words is "thirty-one billion, four hundred three million, twenty-one thousand, two hundred twenty-one".