168277190399921 has 2 divisors, whose sum is σ = 168277190399922. Its totient is φ = 168277190399920.

The previous prime is 168277190399917. The next prime is 168277190400017. The reversal of 168277190399921 is 129993091772861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154492967430400 + 13784222969521 = 12429520^2 + 3712711^2 .

It is an emirp because it is prime and its reverse (129993091772861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168277190399921 - 2² = 168277190399917 is a prime.

It is not a weakly prime, because it can be changed into another prime (168277190396921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84138595199960 + 84138595199961.

It is an arithmetic number, because the mean of its divisors is an integer number (84138595199961).

Almost surely, 2^{168277190399921} is an apocalyptic number.

It is an amenable number.

168277190399921 is a deficient number, since it is larger than the sum of its proper divisors (1).

168277190399921 is an equidigital number, since it uses as much as digits as its factorization.

168277190399921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 185177664, while the sum is 74.

The spelling of 168277190399921 in words is "one hundred sixty-eight trillion, two hundred seventy-seven billion, one hundred ninety million, three hundred ninety-nine thousand, nine hundred twenty-one".