736861221 has 6 divisors (see below), whose sum is σ = 1064355110. Its totient is φ = 491240808.

The previous prime is 736861199. The next prime is 736861231. The reversal of 736861221 is 122168637.

736861221 is a `hidden beast` number, since 7 + 36 + 8 + 612 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 581484996 + 155376225 = 24114^2 + 12465^2 .

It is not a de Polignac number, because 736861221 - 2¹⁴ = 736844837 is a prime.

It is a super-2 number, since 2×736861221² = 1085928918027221682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (736861231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40936726 + ... + 40936743.

Almost surely, 2^736861221 is an apocalyptic number.

It is an amenable number.

736861221 is a deficient number, since it is larger than the sum of its proper divisors (327493889).

736861221 is a wasteful number, since it uses less digits than its factorization.

736861221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81873475 (or 81873472 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 736861221 is about 27145.1878055761. The cubic root of 736861221 is about 903.2235110049.

The spelling of 736861221 in words is "seven hundred thirty-six million, eight hundred sixty-one thousand, two hundred twenty-one".