1225545421 has 2 divisors, whose sum is σ = 1225545422. Its totient is φ = 1225545420.

The previous prime is 1225545383. The next prime is 1225545427. The reversal of 1225545421 is 1245455221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1224020196 + 1525225 = 34986^2 + 1235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225545421 - 2²⁹ = 688674509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225545427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612772710 + 612772711.

It is an arithmetic number, because the mean of its divisors is an integer number (612772711).

Almost surely, 2^1225545421 is an apocalyptic number.

It is an amenable number.

1225545421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225545421 is an equidigital number, since it uses as much as digits as its factorization.

1225545421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16000, while the sum is 31.

The square root of 1225545421 is about 35007.7908614640. The cubic root of 1225545421 is about 1070.1462579936.

The spelling of 1225545421 in words is "one billion, two hundred twenty-five million, five hundred forty-five thousand, four hundred twenty-one".