81535012 has 12 divisors (see below), whose sum is σ = 153662236. Its totient is φ = 37631520.

The previous prime is 81535007. The next prime is 81535033. The reversal of 81535012 is 21053518.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 48080356 + 33454656 = 6934^2 + 5784^2 .

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, 783939 + ... + 784042.

Almost surely, 2^81535012 is an apocalyptic number.

It is an amenable number.

81535012 is a deficient number, since it is larger than the sum of its proper divisors (72127224).

81535012 is a wasteful number, since it uses less digits than its factorization.

81535012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1567998 (or 1567996 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 81535012 is about 9029.6739697511. The cubic root of 81535012 is about 433.6253996845.

The spelling of 81535012 in words is "eighty-one million, five hundred thirty-five thousand, twelve".