38991101221 has 2 divisors, whose sum is σ = 38991101222. Its totient is φ = 38991101220.

The previous prime is 38991101131. The next prime is 38991101231. The reversal of 38991101221 is 12210119983.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29167516225 + 9823584996 = 170785^2 + 99114^2 .

It is an emirp because it is prime and its reverse (12210119983) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 38991101221 - 2²¹ = 38989004069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38991101231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19495550610 + 19495550611.

It is an arithmetic number, because the mean of its divisors is an integer number (19495550611).

Almost surely, 2^38991101221 is an apocalyptic number.

It is an amenable number.

38991101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

38991101221 is an equidigital number, since it uses as much as digits as its factorization.

38991101221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 37.

The spelling of 38991101221 in words is "thirty-eight billion, nine hundred ninety-one million, one hundred one thousand, two hundred twenty-one".