1221426425 has 24 divisors (see below), whose sum is σ = 1571654616. Its totient is φ = 940861440.

The previous prime is 1221426389. The next prime is 1221426433. The reversal of 1221426425 is 5246241221.

It can be written as a sum of positive squares in 12 ways, for example, as 530104576 + 691321849 = 23024^2 + 26293^2 .

It is not a de Polignac number, because 1221426425 - 2³⁰ = 147684601 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82919 + ... + 96531.

It is an arithmetic number, because the mean of its divisors is an integer number (65485609).

Almost surely, 2^1221426425 is an apocalyptic number.

It is an amenable number.

1221426425 is a deficient number, since it is larger than the sum of its proper divisors (350228191).

1221426425 is a wasteful number, since it uses less digits than its factorization.

1221426425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13757 (or 13752 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

The square root of 1221426425 is about 34948.9116425676. The cubic root of 1221426425 is about 1068.9460098982.

Adding to 1221426425 its reverse (5246241221), we get a palindrome (6467667646).

The spelling of 1221426425 in words is "one billion, two hundred twenty-one million, four hundred twenty-six thousand, four hundred twenty-five".