400025531 has 4 divisors (see below), whose sum is σ = 403695600. Its totient is φ = 396355464.

The previous prime is 400025501. The next prime is 400025543. The reversal of 400025531 is 135520004.

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

It is a cyclic number.

It is not a de Polignac number, because 400025531 - 2⁶ = 400025467 is a prime.

It is a super-2 number, since 2×400025531² = 320040850903663922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400025501) 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, 1834871 + ... + 1835088.

It is an arithmetic number, because the mean of its divisors is an integer number (100923900).

Almost surely, 2^400025531 is an apocalyptic number.

400025531 is a deficient number, since it is larger than the sum of its proper divisors (3670069).

400025531 is a wasteful number, since it uses less digits than its factorization.

400025531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3670068.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 400025531 is about 20000.6382648155. The cubic root of 400025531 is about 736.8219755626.

Adding to 400025531 its reverse (135520004), we get a palindrome (535545535).

The spelling of 400025531 in words is "four hundred million, twenty-five thousand, five hundred thirty-one".