81409212 has 30 divisors (see below), whose sum is σ = 212820608. Its totient is φ = 27136296.

The previous prime is 81409189. The next prime is 81409241. The reversal of 81409212 is 21290418.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 125308 + ... + 125955.

Almost surely, 2^81409212 is an apocalyptic number.

It is an amenable number.

81409212 is an abundant number, since it is smaller than the sum of its proper divisors (131411396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81409212 is a wasteful number, since it uses less digits than its factorization.

81409212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251279 (or 251268 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 81409212 is about 9022.7053592589. The cubic root of 81409212 is about 433.4022720037.

The spelling of 81409212 in words is "eighty-one million, four hundred nine thousand, two hundred twelve".