406774808521 has 9 divisors (see below), whose sum is σ = 432121781749. Its totient is φ = 382836673984.

The previous prime is 406774808509. The next prime is 406774808603. The reversal of 406774808521 is 125808477604.

The square root of 406774808521 is 637789.

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

It can be written as a sum of positive squares in 4 ways, for example, as 34796798521 + 371978010000 = 186539^2 + 609900^2 .

It is not a de Polignac number, because 406774808521 - 2¹⁵ = 406774775753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (406774808621) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10823655 + ... + 10861171.

Almost surely, 2^406774808521 is an apocalyptic number.

406774808521 is the 637789-th square number.

406774808521 is the 318895-th centered octagonal number.

It is an amenable number.

406774808521 is a deficient number, since it is larger than the sum of its proper divisors (25346973228).

406774808521 is an frugal number, since it uses more digits than its factorization.

406774808521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75068 (or 37534 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 52.

The spelling of 406774808521 in words is "four hundred six billion, seven hundred seventy-four million, eight hundred eight thousand, five hundred twenty-one".