1125640261 has 6 divisors (see below), whose sum is σ = 1195749650. Its totient is φ = 1059425856.

The previous prime is 1125640213. The next prime is 1125640303. The reversal of 1125640261 is 1620465211.

It can be written as a sum of positive squares in 3 ways, for example, as 627502500 + 498137761 = 25050^2 + 22319^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1125640261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1125640561) 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, 1947186 + ... + 1947763.

Almost surely, 2^1125640261 is an apocalyptic number.

It is an amenable number.

1125640261 is a deficient number, since it is larger than the sum of its proper divisors (70109389).

1125640261 is an equidigital number, since it uses as much as digits as its factorization.

1125640261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3894983 (or 3894966 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1125640261 is about 33550.5627523593. The cubic root of 1125640261 is about 1040.2391773004.

The spelling of 1125640261 in words is "one billion, one hundred twenty-five million, six hundred forty thousand, two hundred sixty-one".