400843519621 has 2 divisors, whose sum is σ = 400843519622. Its totient is φ = 400843519620.

The previous prime is 400843519589. The next prime is 400843519649. The reversal of 400843519621 is 126915348004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 400252349025 + 591170596 = 632655^2 + 24314^2 .

It is a cyclic number.

It is not a de Polignac number, because 400843519621 - 2⁵ = 400843519589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400843549621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200421759810 + 200421759811.

It is an arithmetic number, because the mean of its divisors is an integer number (200421759811).

Almost surely, 2^400843519621 is an apocalyptic number.

It is an amenable number.

400843519621 is a deficient number, since it is larger than the sum of its proper divisors (1).

400843519621 is an equidigital number, since it uses as much as digits as its factorization.

400843519621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 400843519621 in words is "four hundred billion, eight hundred forty-three million, five hundred nineteen thousand, six hundred twenty-one".