2125430721 has 6 divisors (see below), whose sum is σ = 3070066610. Its totient is φ = 1416953808.

The previous prime is 2125430719. The next prime is 2125430731. The reversal of 2125430721 is 1270345212.

It can be written as a sum of positive squares in only one way, i.e., 1661459121 + 463971600 = 40761^2 + 21540^2 .

It is not a de Polignac number, because 2125430721 - 2¹ = 2125430719 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2125430731) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 118079476 + ... + 118079493.

Almost surely, 2^2125430721 is an apocalyptic number.

It is an amenable number.

2125430721 is a deficient number, since it is larger than the sum of its proper divisors (944635889).

2125430721 is a wasteful number, since it uses less digits than its factorization.

2125430721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236158975 (or 236158972 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 2125430721 is about 46102.3938749389. The cubic root of 2125430721 is about 1285.7276525965.

Adding to 2125430721 its reverse (1270345212), we get a palindrome (3395775933).

The spelling of 2125430721 in words is "two billion, one hundred twenty-five million, four hundred thirty thousand, seven hundred twenty-one".