81210006 has 32 divisors (see below), whose sum is σ = 181530720. Its totient is φ = 26910432.

The previous prime is 81209993. The next prime is 81210007. The reversal of 81210006 is 60001218.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81210007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4996 + ... + 13688.

It is an arithmetic number, because the mean of its divisors is an integer number (5672835).

Almost surely, 2^81210006 is an apocalyptic number.

81210006 is an abundant number, since it is smaller than the sum of its proper divisors (100320714).

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

81210006 is a wasteful number, since it uses less digits than its factorization.

81210006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8877 (or 8871 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 81210006 is about 9011.6594476267. The cubic root of 81210006 is about 433.0484756393.

The spelling of 81210006 in words is "eighty-one million, two hundred ten thousand, six".