81511268 has 12 divisors (see below), whose sum is σ = 143671920. Its totient is φ = 40462152.

The previous prime is 81511249. The next prime is 81511271. The reversal of 81511268 is 86211518.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72746 + ... + 73857.

It is an arithmetic number, because the mean of its divisors is an integer number (11972660).

Almost surely, 2^81511268 is an apocalyptic number.

It is an amenable number.

81511268 is a deficient number, since it is larger than the sum of its proper divisors (62160652).

81511268 is a wasteful number, since it uses less digits than its factorization.

81511268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146746 (or 146744 counting only the distinct ones).

The product of its digits is 3840, while the sum is 32.

The square root of 81511268 is about 9028.3590978649. The cubic root of 81511268 is about 433.5833032450.

The spelling of 81511268 in words is "eighty-one million, five hundred eleven thousand, two hundred sixty-eight".