1225126621 has 2 divisors, whose sum is σ = 1225126622. Its totient is φ = 1225126620.

The previous prime is 1225126619. The next prime is 1225126627. The reversal of 1225126621 is 1266215221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 938196900 + 286929721 = 30630^2 + 16939^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225126621 - 2¹ = 1225126619 is a prime.

Together with 1225126619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1225126621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225126627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612563310 + 612563311.

It is an arithmetic number, because the mean of its divisors is an integer number (612563311).

Almost surely, 2^1225126621 is an apocalyptic number.

It is an amenable number.

1225126621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225126621 is an equidigital number, since it uses as much as digits as its factorization.

1225126621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 28.

The square root of 1225126621 is about 35001.8088246879. The cubic root of 1225126621 is about 1070.0243453860.

The spelling of 1225126621 in words is "one billion, two hundred twenty-five million, one hundred twenty-six thousand, six hundred twenty-one".