399881101 has 2 divisors, whose sum is σ = 399881102. Its totient is φ = 399881100.

The previous prime is 399881099. The next prime is 399881113. The reversal of 399881101 is 101188993.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 331422025 + 68459076 = 18205^2 + 8274^2 .

It is an emirp because it is prime and its reverse (101188993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399881101 - 2¹ = 399881099 is a prime.

Together with 399881099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399881161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199940550 + 199940551.

It is an arithmetic number, because the mean of its divisors is an integer number (199940551).

Almost surely, 2^399881101 is an apocalyptic number.

It is an amenable number.

399881101 is a deficient number, since it is larger than the sum of its proper divisors (1).

399881101 is an equidigital number, since it uses as much as digits as its factorization.

399881101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 40.

The square root of 399881101 is about 19997.0273040770. The cubic root of 399881101 is about 736.7332878832.

The spelling of 399881101 in words is "three hundred ninety-nine million, eight hundred eighty-one thousand, one hundred one".