400166539 has 4 divisors (see below), whose sum is σ = 401761080. Its totient is φ = 398572000.

The previous prime is 400166491. The next prime is 400166593. The reversal of 400166539 is 935661004.

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 400166539 - 2¹⁹ = 399642251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400164539) 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, 796894 + ... + 797395.

It is an arithmetic number, because the mean of its divisors is an integer number (100440270).

Almost surely, 2^400166539 is an apocalyptic number.

400166539 is a deficient number, since it is larger than the sum of its proper divisors (1594541).

400166539 is a wasteful number, since it uses less digits than its factorization.

400166539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1594540.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 400166539 is about 20004.1630417271. The cubic root of 400166539 is about 736.9085413603.

The spelling of 400166539 in words is "four hundred million, one hundred sixty-six thousand, five hundred thirty-nine".