406721493 has 28 divisors (see below), whose sum is σ = 611446060. Its totient is φ = 270418176.

The previous prime is 406721479. The next prime is 406721507. The reversal of 406721493 is 394127604.

It is an interprime number because it is at equal distance from previous prime (406721479) and next prime (406721507).

It can be written as a sum of positive squares in 2 ways, for example, as 182979729 + 223741764 = 13527^2 + 14958^2 .

It is not a de Polignac number, because 406721493 - 2⁹ = 406720981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406721453) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 490203 + ... + 491031.

Almost surely, 2^406721493 is an apocalyptic number.

It is an amenable number.

406721493 is a deficient number, since it is larger than the sum of its proper divisors (204724567).

406721493 is an frugal number, since it uses more digits than its factorization.

406721493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 406721493 is about 20167.3372808609. The cubic root of 406721493 is about 740.9104286165.

The spelling of 406721493 in words is "four hundred six million, seven hundred twenty-one thousand, four hundred ninety-three".