31440242421 has 40 divisors (see below), whose sum is σ = 54984963264. Its totient is φ = 17527648320.

The previous prime is 31440242417. The next prime is 31440242423. The reversal of 31440242421 is 12424204413.

31440242421 is a `hidden beast` number, since 3 + 14 + 402 + 4 + 242 + 1 = 666.

It is not a de Polignac number, because 31440242421 - 2² = 31440242417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31440242423) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 652975 + ... + 699468.

Almost surely, 2^31440242421 is an apocalyptic number.

It is an amenable number.

31440242421 is a deficient number, since it is larger than the sum of its proper divisors (23544720843).

31440242421 is a wasteful number, since it uses less digits than its factorization.

31440242421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352503 (or 1352494 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 31440242421 its reverse (12424204413), we get a palindrome (43864446834).

The spelling of 31440242421 in words is "thirty-one billion, four hundred forty million, two hundred forty-two thousand, four hundred twenty-one".