1125213521 has 8 divisors (see below), whose sum is σ = 1174622784. Its totient is φ = 1075844880.

The previous prime is 1125213517. The next prime is 1125213533. The reversal of 1125213521 is 1253125211.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1125213521 - 2² = 1125213517 is a prime.

It is a super-2 number, since 2×1125213521² = 2532210935682434882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1125212521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55586 + ... + 73076.

It is an arithmetic number, because the mean of its divisors is an integer number (146827848).

Almost surely, 2^1125213521 is an apocalyptic number.

It is an amenable number.

1125213521 is a deficient number, since it is larger than the sum of its proper divisors (49409263).

1125213521 is a wasteful number, since it uses less digits than its factorization.

1125213521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20311.

The product of its digits is 600, while the sum is 23.

The square root of 1125213521 is about 33544.2024946189. The cubic root of 1125213521 is about 1040.1077061159.

Adding to 1125213521 its reverse (1253125211), we get a palindrome (2378338732).

The spelling of 1125213521 in words is "one billion, one hundred twenty-five million, two hundred thirteen thousand, five hundred twenty-one".