405809421562944 has 567 divisors, whose sum is σ = 1428275826652311. Its totient is φ = 109825746670080.

The previous prime is 405809421562931. The next prime is 405809421562949. The reversal of 405809421562944 is 449265124908504.

The square root of 405809421562944 is 20144712.

It is a perfect power (a square), and thus also a powerful number.

405809421562944 is a `hidden beast` number, since 4 + 0 + 5 + 8 + 0 + 9 + 4 + 21 + 562 + 9 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (405809421562949) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 64301917549 + ... + 64301923859.

Almost surely, 2^{405809421562944} is an apocalyptic number.

405809421562944 is the 20144712-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405809421562944

405809421562944 is an abundant number, since it is smaller than the sum of its proper divisors (1022466405089367).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

405809421562944 is an frugal number, since it uses more digits than its factorization.

405809421562944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12692 (or 6342 counting only the distinct ones).

The product of its (nonzero) digits is 99532800, while the sum is 63.

The spelling of 405809421562944 in words is "four hundred five trillion, eight hundred nine billion, four hundred twenty-one million, five hundred sixty-two thousand, nine hundred forty-four".