2516431021 has 4 divisors (see below), whose sum is σ = 2710002652. Its totient is φ = 2322859392.

The previous prime is 2516431009. The next prime is 2516431031. The reversal of 2516431021 is 1201346152.

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 1702470121 + 813960900 = 41261^2 + 28530^2 .

It is a cyclic number.

It is not a de Polignac number, because 2516431021 - 2⁷ = 2516430893 is a prime.

It is a super-2 number, since 2×2516431021² = 12664850166902204882, which 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 (2516431031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96785796 + ... + 96785821.

It is an arithmetic number, because the mean of its divisors is an integer number (677500663).

Almost surely, 2^2516431021 is an apocalyptic number.

It is an amenable number.

2516431021 is a deficient number, since it is larger than the sum of its proper divisors (193571631).

2516431021 is a wasteful number, since it uses less digits than its factorization.

2516431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193571630.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 2516431021 is about 50164.0411151255. The cubic root of 2516431021 is about 1360.1756947539.

Adding to 2516431021 its reverse (1201346152), we get a palindrome (3717777173).

The spelling of 2516431021 in words is "two billion, five hundred sixteen million, four hundred thirty-one thousand, twenty-one".