2121365725 has 12 divisors (see below), whose sum is σ = 2669756704. Its totient is φ = 1671761520.

The previous prime is 2121365699. The next prime is 2121365737. The reversal of 2121365725 is 5275631212.

It is a de Polignac number, because none of the positive numbers 2^k-2121365725 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 631569 + ... + 634918.

Almost surely, 2^2121365725 is an apocalyptic number.

2121365725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2121365725 is a deficient number, since it is larger than the sum of its proper divisors (548390979).

2121365725 is a wasteful number, since it uses less digits than its factorization.

2121365725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266564 (or 1266559 counting only the distinct ones).

The product of its digits is 25200, while the sum is 34.

The square root of 2121365725 is about 46058.2861708944. The cubic root of 2121365725 is about 1284.9074559766.

Adding to 2121365725 its reverse (5275631212), we get a palindrome (7396996937).

The spelling of 2121365725 in words is "two billion, one hundred twenty-one million, three hundred sixty-five thousand, seven hundred twenty-five".