81429660 has 288 divisors, whose sum is σ = 297198720. Its totient is φ = 17842176.

The previous prime is 81429613. The next prime is 81429707. The reversal of 81429660 is 6692418.

It is an interprime number because it is at equal distance from previous prime (81429613) and next prime (81429707).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 914896 + ... + 914984.

It is an arithmetic number, because the mean of its divisors is an integer number (1031940).

Almost surely, 2^81429660 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 81429660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148599360).

81429660 is an abundant number, since it is smaller than the sum of its proper divisors (215769060).

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

81429660 is a wasteful number, since it uses less digits than its factorization.

81429660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 81429660 is about 9023.8384294046. The cubic root of 81429660 is about 433.4385556444.

The spelling of 81429660 in words is "eighty-one million, four hundred twenty-nine thousand, six hundred sixty".