81152212 has 6 divisors (see below), whose sum is σ = 142016378. Its totient is φ = 40576104.

The previous prime is 81152207. The next prime is 81152251. The reversal of 81152212 is 21225118.

It can be written as a sum of positive squares in only one way, i.e., 69956496 + 11195716 = 8364^2 + 3346^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10144023 + ... + 10144030.

Almost surely, 2^81152212 is an apocalyptic number.

It is an amenable number.

81152212 is a deficient number, since it is larger than the sum of its proper divisors (60864166).

81152212 is a wasteful number, since it uses less digits than its factorization.

81152212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20288057 (or 20288055 counting only the distinct ones).

The product of its digits is 320, while the sum is 22.

The square root of 81152212 is about 9008.4522533008. The cubic root of 81152212 is about 432.9457233462.

The spelling of 81152212 in words is "eighty-one million, one hundred fifty-two thousand, two hundred twelve".