81214225 has 12 divisors (see below), whose sum is σ = 101434480. Its totient is φ = 64501200.

The previous prime is 81214213. The next prime is 81214279. The reversal of 81214225 is 52241218.

It is not a de Polignac number, because 81214225 - 2⁵ = 81214193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 81214225.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8211 + ... + 15160.

Almost surely, 2^81214225 is an apocalyptic number.

It is an amenable number.

81214225 is a deficient number, since it is larger than the sum of its proper divisors (20220255).

81214225 is a wasteful number, since it uses less digits than its factorization.

81214225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23520 (or 23515 counting only the distinct ones).

The product of its digits is 1280, while the sum is 25.

The square root of 81214225 is about 9011.8935302188. The cubic root of 81214225 is about 433.0559747147.

The spelling of 81214225 in words is "eighty-one million, two hundred fourteen thousand, two hundred twenty-five".