406708781 has 4 divisors (see below), whose sum is σ = 407992092. Its totient is φ = 405425472.

The previous prime is 406708763. The next prime is 406708811. The reversal of 406708781 is 187807604.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 214886281 + 191822500 = 14659^2 + 13850^2 .

It is a cyclic number.

It is not a de Polignac number, because 406708781 - 2⁶ = 406708717 is a prime.

It is a super-2 number, since 2×406708781² = 330824065085011922, 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 (406728781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 641180 + ... + 641813.

It is an arithmetic number, because the mean of its divisors is an integer number (101998023).

Almost surely, 2^406708781 is an apocalyptic number.

It is an amenable number.

406708781 is a deficient number, since it is larger than the sum of its proper divisors (1283311).

406708781 is a wasteful number, since it uses less digits than its factorization.

406708781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283310.

The product of its (nonzero) digits is 75264, while the sum is 41.

The square root of 406708781 is about 20167.0221153248. The cubic root of 406708781 is about 740.9027095330.

The spelling of 406708781 in words is "four hundred six million, seven hundred eight thousand, seven hundred eighty-one".