405437981 has 16 divisors (see below), whose sum is σ = 467100144. Its totient is φ = 348585984.

The previous prime is 405437939. The next prime is 405437993. The reversal of 405437981 is 189734504.

It can be written as a sum of positive squares in 8 ways, for example, as 21473956 + 383964025 = 4634^2 + 19595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405437981 is a prime.

It is a super-2 number, since 2×405437981² = 328759912874712722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405437281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11981 + ... + 30893.

It is an arithmetic number, because the mean of its divisors is an integer number (29193759).

Almost surely, 2^405437981 is an apocalyptic number.

It is an amenable number.

405437981 is a deficient number, since it is larger than the sum of its proper divisors (61662163).

405437981 is a wasteful number, since it uses less digits than its factorization.

405437981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19040.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 405437981 is about 20135.4905825510. The cubic root of 405437981 is about 740.1302309145.

The spelling of 405437981 in words is "four hundred five million, four hundred thirty-seven thousand, nine hundred eighty-one".