81429487 has 8 divisors (see below), whose sum is σ = 84381440. Its totient is φ = 78525720.

The previous prime is 81429443. The next prime is 81429503. The reversal of 81429487 is 78492418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81429487 is a prime.

It is a super-2 number, since 2×81429487² = 13261522706166338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81429437) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8589 + ... + 15382.

It is an arithmetic number, because the mean of its divisors is an integer number (10547680).

Almost surely, 2^81429487 is an apocalyptic number.

81429487 is a deficient number, since it is larger than the sum of its proper divisors (2951953).

81429487 is a wasteful number, since it uses less digits than its factorization.

81429487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24093.

The product of its digits is 129024, while the sum is 43.

The square root of 81429487 is about 9023.8288436783. The cubic root of 81429487 is about 433.4382486926.

The spelling of 81429487 in words is "eighty-one million, four hundred twenty-nine thousand, four hundred eighty-seven".