81005662 has 4 divisors (see below), whose sum is σ = 121508496. Its totient is φ = 40502830.

The previous prime is 81005657. The next prime is 81005681. The reversal of 81005662 is 26650018.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 81005662.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20251414 + ... + 20251417.

It is an arithmetic number, because the mean of its divisors is an integer number (30377124).

Almost surely, 2^81005662 is an apocalyptic number.

81005662 is a deficient number, since it is larger than the sum of its proper divisors (40502834).

81005662 is a wasteful number, since it uses less digits than its factorization.

81005662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40502833.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 81005662 is about 9000.3145500588. The cubic root of 81005662 is about 432.6849523599.

The spelling of 81005662 in words is "eighty-one million, five thousand, six hundred sixty-two".