25321221649 has 2 divisors, whose sum is σ = 25321221650. Its totient is φ = 25321221648.

The previous prime is 25321221641. The next prime is 25321221683. The reversal of 25321221649 is 94612212352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25199340049 + 121881600 = 158743^2 + 11040^2 .

It is a cyclic number.

It is not a de Polignac number, because 25321221649 - 2³ = 25321221641 is a prime.

It is not a weakly prime, because it can be changed into another prime (25321221641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12660610824 + 12660610825.

It is an arithmetic number, because the mean of its divisors is an integer number (12660610825).

Almost surely, 2^25321221649 is an apocalyptic number.

It is an amenable number.

25321221649 is a deficient number, since it is larger than the sum of its proper divisors (1).

25321221649 is an equidigital number, since it uses as much as digits as its factorization.

25321221649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 37.

The spelling of 25321221649 in words is "twenty-five billion, three hundred twenty-one million, two hundred twenty-one thousand, six hundred forty-nine".