81214380 has 192 divisors, whose sum is σ = 284497920. Its totient is φ = 19084032.

The previous prime is 81214337. The next prime is 81214381. The reversal of 81214380 is 8341218.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81214381) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 161209 + ... + 161711.

It is an arithmetic number, because the mean of its divisors is an integer number (1481760).

Almost surely, 2^81214380 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81214380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142248960).

81214380 is an abundant number, since it is smaller than the sum of its proper divisors (203283540).

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

81214380 is a wasteful number, since it uses less digits than its factorization.

81214380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557 (or 549 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 81214380 is about 9011.9021299612. The cubic root of 81214380 is about 433.0562502150.

Adding to 81214380 its reverse (8341218), we get a palindrome (89555598).

The spelling of 81214380 in words is "eighty-one million, two hundred fourteen thousand, three hundred eighty".