400720069 has 2 divisors, whose sum is σ = 400720070. Its totient is φ = 400720068.

The previous prime is 400720031. The next prime is 400720093. The reversal of 400720069 is 960027004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393228900 + 7491169 = 19830^2 + 2737^2 .

It is a cyclic number.

It is not a de Polignac number, because 400720069 - 2¹³ = 400711877 is a prime.

It is a super-2 number, since 2×400720069² = 321153147398729522, which contains 22 as substring.

It is equal to p_21372616 and since 400720069 and 21372616 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400720169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200360034 + 200360035.

It is an arithmetic number, because the mean of its divisors is an integer number (200360035).

Almost surely, 2^400720069 is an apocalyptic number.

It is an amenable number.

400720069 is a deficient number, since it is larger than the sum of its proper divisors (1).

400720069 is an equidigital number, since it uses as much as digits as its factorization.

400720069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 400720069 is about 20017.9936307313. The cubic root of 400720069 is about 737.2481608382.

The spelling of 400720069 in words is "four hundred million, seven hundred twenty thousand, sixty-nine".