406465921 has 3 divisors (see below), whose sum is σ = 406486083. Its totient is φ = 406445760.

The previous prime is 406465909. The next prime is 406465931. The reversal of 406465921 is 129564604.

The square root of 406465921 is 20161.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 265331521 + 141134400 = 16289^2 + 11880^2 .

It is not a de Polignac number, because 406465921 - 2¹³ = 406457729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (406465931) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 10081 + ... + 30241.

It is an arithmetic number, because the mean of its divisors is an integer number (135495361).

Almost surely, 2^406465921 is an apocalyptic number.

406465921 is the 20161-st square number.

406465921 is the 10081-st centered octagonal number.

It is an amenable number.

406465921 is a deficient number, since it is larger than the sum of its proper divisors (20162).

406465921 is an frugal number, since it uses more digits than its factorization.

406465921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40322 (or 20161 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The cubic root of 406465921 is about 740.7552072188.

The spelling of 406465921 in words is "four hundred six million, four hundred sixty-five thousand, nine hundred twenty-one".