8690220981 has 24 divisors (see below), whose sum is σ = 13542492600. Its totient is φ = 5338187136.

The previous prime is 8690220977. The next prime is 8690221013. The reversal of 8690220981 is 1890220968.

It can be written as a sum of positive squares in 4 ways, for example, as 374422500 + 8315798481 = 19350^2 + 91191^2 .

It is not a de Polignac number, because 8690220981 - 2² = 8690220977 is a prime.

It is a super-2 number, since 2×8690220981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8690220941) 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, 1506 + ... + 131843.

It is an arithmetic number, because the mean of its divisors is an integer number (564270525).

Almost surely, 2^8690220981 is an apocalyptic number.

It is an amenable number.

8690220981 is a deficient number, since it is larger than the sum of its proper divisors (4852271619).

8690220981 is a wasteful number, since it uses less digits than its factorization.

8690220981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133925 (or 133922 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 8690220981 is about 93221.3547477186. The cubic root of 8690220981 is about 2055.9392293207.

The spelling of 8690220981 in words is "eight billion, six hundred ninety million, two hundred twenty thousand, nine hundred eighty-one".