400681493 has 4 divisors (see below), whose sum is σ = 404357580. Its totient is φ = 397005408.

The previous prime is 400681469. The next prime is 400681513. The reversal of 400681493 is 394186004.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 151609969 + 249071524 = 12313^2 + 15782^2 .

It is a cyclic number.

It is not a de Polignac number, because 400681493 - 2²⁰ = 399632917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400681403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1837880 + ... + 1838097.

It is an arithmetic number, because the mean of its divisors is an integer number (101089395).

Almost surely, 2^400681493 is an apocalyptic number.

It is an amenable number.

400681493 is a deficient number, since it is larger than the sum of its proper divisors (3676087).

400681493 is a wasteful number, since it uses less digits than its factorization.

400681493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3676086.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 400681493 is about 20017.0300744141. The cubic root of 400681493 is about 737.2245025957.

The spelling of 400681493 in words is "four hundred million, six hundred eighty-one thousand, four hundred ninety-three".