736491221 has 16 divisors (see below), whose sum is σ = 815073840. Its totient is φ = 662323200.

The previous prime is 736491199. The next prime is 736491263. The reversal of 736491221 is 122194637.

It can be written as a sum of positive squares in 8 ways, for example, as 161163025 + 575328196 = 12695^2 + 23986^2 .

It is a cyclic number.

It is not a de Polignac number, because 736491221 - 2¹⁸ = 736229077 is a prime.

It is a super-2 number, since 2×736491221² = 1084838637220141682, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (736491271) 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, 40121 + ... + 55521.

It is an arithmetic number, because the mean of its divisors is an integer number (50942115).

Almost surely, 2^736491221 is an apocalyptic number.

It is an amenable number.

736491221 is a deficient number, since it is larger than the sum of its proper divisors (78582619).

736491221 is a wasteful number, since it uses less digits than its factorization.

736491221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15544.

The product of its digits is 18144, while the sum is 35.

The square root of 736491221 is about 27138.3717455561. The cubic root of 736491221 is about 903.0723072046.

The spelling of 736491221 in words is "seven hundred thirty-six million, four hundred ninety-one thousand, two hundred twenty-one".