1047125721 has 4 divisors (see below), whose sum is σ = 1396167632. Its totient is φ = 698083812.

The previous prime is 1047125711. The next prime is 1047125747. The reversal of 1047125721 is 1275217401.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-1047125721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1047125711) 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, 174520951 + ... + 174520956.

It is an arithmetic number, because the mean of its divisors is an integer number (349041908).

Almost surely, 2^1047125721 is an apocalyptic number.

It is an amenable number.

1047125721 is a deficient number, since it is larger than the sum of its proper divisors (349041911).

1047125721 is an equidigital number, since it uses as much as digits as its factorization.

1047125721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349041910.

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 1047125721 is about 32359.3220108209. The cubic root of 1047125721 is about 1015.4680785736.

The spelling of 1047125721 in words is "one billion, forty-seven million, one hundred twenty-five thousand, seven hundred twenty-one".