81901654 has 4 divisors (see below), whose sum is σ = 122852484. Its totient is φ = 40950826.

The previous prime is 81901649. The next prime is 81901667. The reversal of 81901654 is 45610918.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20475412 + ... + 20475415.

It is an arithmetic number, because the mean of its divisors is an integer number (30713121).

Almost surely, 2^81901654 is an apocalyptic number.

81901654 is a deficient number, since it is larger than the sum of its proper divisors (40950830).

81901654 is a wasteful number, since it uses less digits than its factorization.

81901654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40950829.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 81901654 is about 9049.9532595478. The cubic root of 81901654 is about 434.2743952024.

The spelling of 81901654 in words is "eighty-one million, nine hundred one thousand, six hundred fifty-four".