81019436 has 12 divisors (see below), whose sum is σ = 141869112. Its totient is φ = 40485408.

The previous prime is 81019429. The next prime is 81019447. The reversal of 81019436 is 63491018.

It is a happy number.

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, 2891 + ... + 13053.

It is an arithmetic number, because the mean of its divisors is an integer number (11822426).

Almost surely, 2^81019436 is an apocalyptic number.

It is an amenable number.

81019436 is a deficient number, since it is larger than the sum of its proper divisors (60849676).

81019436 is a wasteful number, since it uses less digits than its factorization.

81019436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12160 (or 12158 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 81019436 is about 9001.0797130122. The cubic root of 81019436 is about 432.7094751921.

The spelling of 81019436 in words is "eighty-one million, nineteen thousand, four hundred thirty-six".