1225621531 has 2 divisors, whose sum is σ = 1225621532. Its totient is φ = 1225621530.

The previous prime is 1225621489. The next prime is 1225621541. The reversal of 1225621531 is 1351265221.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1225621531 is a prime.

It is a super-2 number, since 2×1225621531² = 3004296274501567922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1225621531.

It is not a weakly prime, because it can be changed into another prime (1225621541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612810765 + 612810766.

It is an arithmetic number, because the mean of its divisors is an integer number (612810766).

Almost surely, 2^1225621531 is an apocalyptic number.

1225621531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225621531 is an equidigital number, since it uses as much as digits as its factorization.

1225621531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 28.

The square root of 1225621531 is about 35008.8778883300. The cubic root of 1225621531 is about 1070.1684106189.

Adding to 1225621531 its reverse (1351265221), we get a palindrome (2576886752).

The spelling of 1225621531 in words is "one billion, two hundred twenty-five million, six hundred twenty-one thousand, five hundred thirty-one".