400259821 has 8 divisors (see below), whose sum is σ = 442699544. Its totient is φ = 359484480.

The previous prime is 400259819. The next prime is 400259837. The reversal of 400259821 is 128952004.

It can be written as a sum of positive squares in 4 ways, for example, as 16491721 + 383768100 = 4061^2 + 19590^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400259821 - 2¹ = 400259819 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 (400259861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 415590 + ... + 416551.

It is an arithmetic number, because the mean of its divisors is an integer number (55337443).

Almost surely, 2^400259821 is an apocalyptic number.

It is an amenable number.

400259821 is a deficient number, since it is larger than the sum of its proper divisors (42439723).

400259821 is a wasteful number, since it uses less digits than its factorization.

400259821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832191.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 400259821 is about 20006.4944705463. The cubic root of 400259821 is about 736.9657966572.

The spelling of 400259821 in words is "four hundred million, two hundred fifty-nine thousand, eight hundred twenty-one".