31144021 has 4 divisors (see below), whose sum is σ = 32783200. Its totient is φ = 29504844.

The previous prime is 31143971. The next prime is 31144027. The reversal of 31144021 is 12044113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12044113 = 773 ⋅15581.

It is a cyclic number.

It is not a de Polignac number, because 31144021 - 2¹¹ = 31141973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31143986 and 31144004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31144027) 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, 819561 + ... + 819598.

It is an arithmetic number, because the mean of its divisors is an integer number (8195800).

Almost surely, 2^31144021 is an apocalyptic number.

It is an amenable number.

31144021 is a deficient number, since it is larger than the sum of its proper divisors (1639179).

31144021 is a wasteful number, since it uses less digits than its factorization.

31144021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639178.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 31144021 is about 5580.6828435237. The cubic root of 31144021 is about 314.6237920723.

Adding to 31144021 its reverse (12044113), we get a palindrome (43188134).

The spelling of 31144021 in words is "thirty-one million, one hundred forty-four thousand, twenty-one".