15548279221 has 2 divisors, whose sum is σ = 15548279222. Its totient is φ = 15548279220.

The previous prime is 15548279213. The next prime is 15548279249. The reversal of 15548279221 is 12297284551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15132690225 + 415588996 = 123015^2 + 20386^2 .

It is a cyclic number.

It is not a de Polignac number, because 15548279221 - 2³ = 15548279213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15548279251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7774139610 + 7774139611.

It is an arithmetic number, because the mean of its divisors is an integer number (7774139611).

Almost surely, 2^15548279221 is an apocalyptic number.

It is an amenable number.

15548279221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15548279221 is an equidigital number, since it uses as much as digits as its factorization.

15548279221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 46.

The spelling of 15548279221 in words is "fifteen billion, five hundred forty-eight million, two hundred seventy-nine thousand, two hundred twenty-one".