400540551 has 4 divisors (see below), whose sum is σ = 534054072. Its totient is φ = 267027032.

The previous prime is 400540549. The next prime is 400540573. The reversal of 400540551 is 155045004.

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 400540551 - 2¹ = 400540549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400540531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66756756 + ... + 66756761.

It is an arithmetic number, because the mean of its divisors is an integer number (133513518).

Almost surely, 2^400540551 is an apocalyptic number.

400540551 is a deficient number, since it is larger than the sum of its proper divisors (133513521).

400540551 is a wasteful number, since it uses less digits than its factorization.

400540551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133513520.

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 400540551 is about 20013.5092125294. The cubic root of 400540551 is about 737.1380514841.

Adding to 400540551 its reverse (155045004), we get a palindrome (555585555).

The spelling of 400540551 in words is "four hundred million, five hundred forty thousand, five hundred fifty-one".