807721221 has 8 divisors (see below), whose sum is σ = 1140312384. Its totient is φ = 506805440.

The previous prime is 807721207. The next prime is 807721249. The reversal of 807721221 is 122127708.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-807721221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (807723221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7918785 + ... + 7918886.

It is an arithmetic number, because the mean of its divisors is an integer number (142539048).

Almost surely, 2^807721221 is an apocalyptic number.

It is an amenable number.

807721221 is a deficient number, since it is larger than the sum of its proper divisors (332591163).

807721221 is a wasteful number, since it uses less digits than its factorization.

807721221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15837691.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 807721221 is about 28420.4366785593. The cubic root of 807721221 is about 931.2947707197.

Adding to 807721221 its reverse (122127708), we get a palindrome (929848929).

The spelling of 807721221 in words is "eight hundred seven million, seven hundred twenty-one thousand, two hundred twenty-one".