1221421325 has 18 divisors (see below), whose sum is σ = 1583293194. Its totient is φ = 934642720.

The previous prime is 1221421309. The next prime is 1221421339. The reversal of 1221421325 is 5231241221.

It can be written as a sum of positive squares in 3 ways, for example, as 127531849 + 1093889476 = 11293^2 + 33074^2 .

It is not a de Polignac number, because 1221421325 - 2⁴ = 1221421309 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221421325.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 32954 + ... + 59403.

It is an arithmetic number, because the mean of its divisors is an integer number (87960733).

Almost surely, 2^1221421325 is an apocalyptic number.

It is an amenable number.

1221421325 is a deficient number, since it is larger than the sum of its proper divisors (361871869).

1221421325 is an equidigital number, since it uses as much as digits as its factorization.

1221421325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92413 (or 92385 counting only the distinct ones).

The product of its digits is 960, while the sum is 23.

The square root of 1221421325 is about 34948.8386788460. The cubic root of 1221421325 is about 1068.9445221207.

Adding to 1221421325 its reverse (5231241221), we get a palindrome (6452662546).

The spelling of 1221421325 in words is "one billion, two hundred twenty-one million, four hundred twenty-one thousand, three hundred twenty-five".