81474280969 has 27 divisors (see below), whose sum is σ = 87520096359. Its totient is φ = 75834902160.

The previous prime is 81474280939. The next prime is 81474280991. The reversal of 81474280969 is 96908247418.

The square root of 81474280969 is 285437.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 897781369 + 80576499600 = 29963^2 + 283860^2 .

It is not a de Polignac number, because 81474280969 - 2⁷ = 81474280841 is a prime.

It is a super-2 number, since 2×81474280969² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81474280919) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 450134059 + ... + 450134239.

Almost surely, 2^81474280969 is an apocalyptic number.

81474280969 is the 285437-th square number.

81474280969 is the 142719-th centered octagonal number.

It is an amenable number.

81474280969 is a deficient number, since it is larger than the sum of its proper divisors (6045815390).

81474280969 is an frugal number, since it uses more digits than its factorization.

81474280969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 58.

The spelling of 81474280969 in words is "eighty-one billion, four hundred seventy-four million, two hundred eighty thousand, nine hundred sixty-nine".