15445416221 has 2 divisors, whose sum is σ = 15445416222. Its totient is φ = 15445416220.

The previous prime is 15445416199. The next prime is 15445416253. The reversal of 15445416221 is 12261454451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11382756100 + 4062660121 = 106690^2 + 63739^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15445416221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15445416821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7722708110 + 7722708111.

It is an arithmetic number, because the mean of its divisors is an integer number (7722708111).

Almost surely, 2^15445416221 is an apocalyptic number.

It is an amenable number.

15445416221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15445416221 is an equidigital number, since it uses as much as digits as its factorization.

15445416221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38400, while the sum is 35.

The spelling of 15445416221 in words is "fifteen billion, four hundred forty-five million, four hundred sixteen thousand, two hundred twenty-one".