2153121631 has 4 divisors (see below), whose sum is σ = 2153663512. Its totient is φ = 2152579752.

The previous prime is 2153121611. The next prime is 2153121637. The reversal of 2153121631 is 1361213512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2153121631 - 2⁹ = 2153121119 is a prime.

It is a super-2 number, since 2×2153121631² = 9271865515760200322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2153121596 and 2153121605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2153121637) 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, 264936 + ... + 272941.

It is an arithmetic number, because the mean of its divisors is an integer number (538415878).

Almost surely, 2^2153121631 is an apocalyptic number.

2153121631 is a deficient number, since it is larger than the sum of its proper divisors (541881).

2153121631 is an equidigital number, since it uses as much as digits as its factorization.

2153121631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541880.

The product of its digits is 1080, while the sum is 25.

The square root of 2153121631 is about 46401.7416806740. The cubic root of 2153121631 is about 1291.2872256217.

The spelling of 2153121631 in words is "two billion, one hundred fifty-three million, one hundred twenty-one thousand, six hundred thirty-one".