81420888 has 64 divisors (see below), whose sum is σ = 216833760. Its totient is φ = 25389056.

The previous prime is 81420853. The next prime is 81420917. The reversal of 81420888 is 88802418.

It is a super-2 number, since 2×81420888² = 13258722005417088, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79870 + ... + 80882.

Almost surely, 2^81420888 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 81420888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108416880).

81420888 is an abundant number, since it is smaller than the sum of its proper divisors (135412872).

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

81420888 is a wasteful number, since it uses less digits than its factorization.

81420888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1236 (or 1232 counting only the distinct ones).

The product of its (nonzero) digits is 32768, while the sum is 39.

The square root of 81420888 is about 9023.3523703777. The cubic root of 81420888 is about 433.4229910473.

The spelling of 81420888 in words is "eighty-one million, four hundred twenty thousand, eight hundred eighty-eight".