15222778955981 has 2 divisors, whose sum is σ = 15222778955982. Its totient is φ = 15222778955980.

The previous prime is 15222778955977. The next prime is 15222778956001. The reversal of 15222778955981 is 18955987722251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15195573422500 + 27205533481 = 3898150^2 + 164941^2 .

It is a cyclic number.

It is not a de Polignac number, because 15222778955981 - 2² = 15222778955977 is a prime.

It is a super-2 number, since 2×15222778955981² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15222778955911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7611389477990 + 7611389477991.

It is an arithmetic number, because the mean of its divisors is an integer number (7611389477991).

Almost surely, 2^{15222778955981} is an apocalyptic number.

It is an amenable number.

15222778955981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15222778955981 is an equidigital number, since it uses as much as digits as its factorization.

15222778955981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016000, while the sum is 71.

The spelling of 15222778955981 in words is "fifteen trillion, two hundred twenty-two billion, seven hundred seventy-eight million, nine hundred fifty-five thousand, nine hundred eighty-one".