400435981 has 4 divisors (see below), whose sum is σ = 436839264. Its totient is φ = 364032700.

The previous prime is 400435967. The next prime is 400435991. The reversal of 400435981 is 189534004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 400435981 - 2¹³ = 400427789 is a prime.

It is a super-2 number, since 2×400435981² = 320697949758864722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400435921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18201625 + ... + 18201646.

It is an arithmetic number, because the mean of its divisors is an integer number (109209816).

Almost surely, 2^400435981 is an apocalyptic number.

It is an amenable number.

400435981 is a deficient number, since it is larger than the sum of its proper divisors (36403283).

400435981 is a wasteful number, since it uses less digits than its factorization.

400435981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36403282.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 400435981 is about 20010.8965566263. The cubic root of 400435981 is about 737.0738971516.

Adding to 400435981 its reverse (189534004), we get a palindrome (589969985).

The spelling of 400435981 in words is "four hundred million, four hundred thirty-five thousand, nine hundred eighty-one".