400691897 has 2 divisors, whose sum is σ = 400691898. Its totient is φ = 400691896.

The previous prime is 400691891. The next prime is 400691899. The reversal of 400691897 is 798196004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 369062521 + 31629376 = 19211^2 + 5624^2 .

It is a cyclic number.

It is not a de Polignac number, because 400691897 - 2⁴ = 400691881 is a prime.

Together with 400691899, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400691891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200345948 + 200345949.

It is an arithmetic number, because the mean of its divisors is an integer number (200345949).

Almost surely, 2^400691897 is an apocalyptic number.

It is an amenable number.

400691897 is a deficient number, since it is larger than the sum of its proper divisors (1).

400691897 is an equidigital number, since it uses as much as digits as its factorization.

400691897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 400691897 is about 20017.2899514395. The cubic root of 400691897 is about 737.2308834056.

The spelling of 400691897 in words is "four hundred million, six hundred ninety-one thousand, eight hundred ninety-seven".