91563444 has 72 divisors (see below), whose sum is σ = 266692608. Its totient is φ = 25945920.

The previous prime is 91563443. The next prime is 91563481. The reversal of 91563444 is 44436519.

91563444 is a `hidden beast` number, since 9 + 15 + 634 + 4 + 4 = 666.

It is a super-2 number, since 2×91563444² = 16767728554282272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 91563399 and 91563408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91563443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30574 + ... + 33434.

It is an arithmetic number, because the mean of its divisors is an integer number (3704064).

Almost surely, 2^91563444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91563444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133346304).

91563444 is an abundant number, since it is smaller than the sum of its proper divisors (175129164).

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

91563444 is a wasteful number, since it uses less digits than its factorization.

91563444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3005 (or 3000 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 91563444 is about 9568.8789312019. The cubic root of 91563444 is about 450.7205640969.

The spelling of 91563444 in words is "ninety-one million, five hundred sixty-three thousand, four hundred forty-four".