81267642 has 12 divisors (see below), whose sum is σ = 176079930. Its totient is φ = 27089208.

The previous prime is 81267629. The next prime is 81267643. The reversal of 81267642 is 24676218.

81267642 is a `hidden beast` number, since 8 + 1 + 2 + 6 + 7 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 76895361 + 4372281 = 8769^2 + 2091^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81267597 and 81267606.

It is not an unprimeable number, because it can be changed into a prime (81267643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2257417 + ... + 2257452.

Almost surely, 2^81267642 is an apocalyptic number.

81267642 is an abundant number, since it is smaller than the sum of its proper divisors (94812288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81267642 is a wasteful number, since it uses less digits than its factorization.

81267642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4514877 (or 4514874 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 81267642 is about 9014.8567376304. The cubic root of 81267642 is about 433.1508984845.

The spelling of 81267642 in words is "eighty-one million, two hundred sixty-seven thousand, six hundred forty-two".