400543669 has 2 divisors, whose sum is σ = 400543670. Its totient is φ = 400543668.

The previous prime is 400543639. The next prime is 400543697. The reversal of 400543669 is 966345004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390852900 + 9690769 = 19770^2 + 3113^2 .

It is a cyclic number.

It is not a de Polignac number, because 400543669 - 2¹¹ = 400541621 is a prime.

It is a super-2 number, since 2×400543669² = 320870461551963122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400543639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200271834 + 200271835.

It is an arithmetic number, because the mean of its divisors is an integer number (200271835).

Almost surely, 2^400543669 is an apocalyptic number.

It is an amenable number.

400543669 is a deficient number, since it is larger than the sum of its proper divisors (1).

400543669 is an equidigital number, since it uses as much as digits as its factorization.

400543669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 400543669 is about 20013.5871097612. The cubic root of 400543669 is about 737.1399642246.

It can be divided in two parts, 4005 and 43669, that added together give a palindrome (47674).

The spelling of 400543669 in words is "four hundred million, five hundred forty-three thousand, six hundred sixty-nine".