400022621 has 2 divisors, whose sum is σ = 400022622. Its totient is φ = 400022620.

The previous prime is 400022587. The next prime is 400022633. The reversal of 400022621 is 126220004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250082596 + 149940025 = 15814^2 + 12245^2 .

It is a cyclic number.

It is not a de Polignac number, because 400022621 - 2²² = 395828317 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400022621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400022671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200011310 + 200011311.

It is an arithmetic number, because the mean of its divisors is an integer number (200011311).

Almost surely, 2^400022621 is an apocalyptic number.

It is an amenable number.

400022621 is a deficient number, since it is larger than the sum of its proper divisors (1).

400022621 is an equidigital number, since it uses as much as digits as its factorization.

400022621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 400022621 is about 20000.5655170048. The cubic root of 400022621 is about 736.8201888790.

Adding to 400022621 its reverse (126220004), we get a palindrome (526242625).

The spelling of 400022621 in words is "four hundred million, twenty-two thousand, six hundred twenty-one".