1225132021 has 4 divisors (see below), whose sum is σ = 1227484044. Its totient is φ = 1222780000.

The previous prime is 1225132001. The next prime is 1225132039. The reversal of 1225132021 is 1202315221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1202315221 = 163 ⋅7376167.

It can be written as a sum of positive squares in 2 ways, for example, as 552767121 + 672364900 = 23511^2 + 25930^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225132021 - 2⁷ = 1225131893 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1225132021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225132001) 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, 1175230 + ... + 1176271.

It is an arithmetic number, because the mean of its divisors is an integer number (306871011).

Almost surely, 2^1225132021 is an apocalyptic number.

It is an amenable number.

1225132021 is a deficient number, since it is larger than the sum of its proper divisors (2352023).

1225132021 is an equidigital number, since it uses as much as digits as its factorization.

1225132021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2352022.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1225132021 is about 35001.8859634735. The cubic root of 1225132021 is about 1070.0259175019.

Adding to 1225132021 its reverse (1202315221), we get a palindrome (2427447242).

The spelling of 1225132021 in words is "one billion, two hundred twenty-five million, one hundred thirty-two thousand, twenty-one".