91781654 has 4 divisors (see below), whose sum is σ = 137672484. Its totient is φ = 45890826.

The previous prime is 91781617. The next prime is 91781663. The reversal of 91781654 is 45618719.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 22945412 + ... + 22945415.

It is an arithmetic number, because the mean of its divisors is an integer number (34418121).

Almost surely, 2^91781654 is an apocalyptic number.

91781654 is a deficient number, since it is larger than the sum of its proper divisors (45890830).

91781654 is a wasteful number, since it uses less digits than its factorization.

91781654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45890829.

The product of its digits is 60480, while the sum is 41.

The square root of 91781654 is about 9580.2742131945. The cubic root of 91781654 is about 451.0783258996.

The spelling of 91781654 in words is "ninety-one million, seven hundred eighty-one thousand, six hundred fifty-four".