401215128991 has 2 divisors, whose sum is σ = 401215128992. Its totient is φ = 401215128990.

The previous prime is 401215128953. The next prime is 401215129043. The reversal of 401215128991 is 199821512104.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 401215128991 - 2¹³ = 401215120799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401215128931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200607564495 + 200607564496.

It is an arithmetic number, because the mean of its divisors is an integer number (200607564496).

Almost surely, 2^401215128991 is an apocalyptic number.

401215128991 is a deficient number, since it is larger than the sum of its proper divisors (1).

401215128991 is an equidigital number, since it uses as much as digits as its factorization.

401215128991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 43.

The spelling of 401215128991 in words is "four hundred one billion, two hundred fifteen million, one hundred twenty-eight thousand, nine hundred ninety-one".