91561470 has 128 divisors (see below), whose sum is σ = 295142400. Its totient is φ = 17556480.

The previous prime is 91561447. The next prime is 91561471. The reversal of 91561470 is 7416519.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91561471) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28506 + ... + 31554.

It is an arithmetic number, because the mean of its divisors is an integer number (2305800).

Almost surely, 2^91561470 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91561470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147571200).

91561470 is an abundant number, since it is smaller than the sum of its proper divisors (203580930).

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

91561470 is a wasteful number, since it uses less digits than its factorization.

91561470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3090.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 91561470 is about 9568.7757837667. The cubic root of 91561470 is about 450.7173250721.

Adding to 91561470 its reverse (7416519), we get a palindrome (98977989).

The spelling of 91561470 in words is "ninety-one million, five hundred sixty-one thousand, four hundred seventy".