31401047021 has 4 divisors (see below), whose sum is σ = 33248167452. Its totient is φ = 29553926592.

The previous prime is 31401047011. The next prime is 31401047081. The reversal of 31401047021 is 12074010413.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26606176996 + 4794870025 = 163114^2 + 69245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31401047021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31401047011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 923560190 + ... + 923560223.

It is an arithmetic number, because the mean of its divisors is an integer number (8312041863).

Almost surely, 2^31401047021 is an apocalyptic number.

It is an amenable number.

31401047021 is a deficient number, since it is larger than the sum of its proper divisors (1847120431).

31401047021 is a wasteful number, since it uses less digits than its factorization.

31401047021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1847120430.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 31401047021 its reverse (12074010413), we get a palindrome (43475057434).

The spelling of 31401047021 in words is "thirty-one billion, four hundred one million, forty-seven thousand, twenty-one".