8007721281 has 24 divisors (see below), whose sum is σ = 13224466944. Its totient is φ = 4573981440.

The previous prime is 8007721237. The next prime is 8007721291. The reversal of 8007721281 is 1821277008.

It is a happy number.

It is not a de Polignac number, because 8007721281 - 2⁷ = 8007721153 is a prime.

It is a super-2 number, since 2×8007721281² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8007721291) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138705 + ... + 187761.

It is an arithmetic number, because the mean of its divisors is an integer number (551019456).

Almost surely, 2^8007721281 is an apocalyptic number.

It is an amenable number.

8007721281 is a deficient number, since it is larger than the sum of its proper divisors (5216745663).

8007721281 is a wasteful number, since it uses less digits than its factorization.

8007721281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51661 (or 51658 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 8007721281 is about 89485.8719631205. The cubic root of 8007721281 is about 2000.6432331867.

Adding to 8007721281 its reverse (1821277008), we get a palindrome (9828998289).

The spelling of 8007721281 in words is "eight billion, seven million, seven hundred twenty-one thousand, two hundred eighty-one".