89491781 has 8 divisors (see below), whose sum is σ = 93861504. Its totient is φ = 85162000.

The previous prime is 89491777. The next prime is 89491813. The reversal of 89491781 is 18719498.

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

It is a cyclic number.

It is not a de Polignac number, because 89491781 - 2² = 89491777 is a prime.

It is a super-2 number, since 2×89491781² = 16017557733103922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (89491741) 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, 5345 + ... + 14406.

It is an arithmetic number, because the mean of its divisors is an integer number (11732688).

Almost surely, 2^89491781 is an apocalyptic number.

It is an amenable number.

89491781 is a deficient number, since it is larger than the sum of its proper divisors (4369723).

89491781 is a wasteful number, since it uses less digits than its factorization.

89491781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19971.

The product of its digits is 145152, while the sum is 47.

The square root of 89491781 is about 9460.0095665914. The cubic root of 89491781 is about 447.2953503868.

The spelling of 89491781 in words is "eighty-nine million, four hundred ninety-one thousand, seven hundred eighty-one".