91651287 has 16 divisors (see below), whose sum is σ = 150402560. Its totient is φ = 48343392.

The previous prime is 91651253. The next prime is 91651303. The reversal of 91651287 is 78215619.

It is not a de Polignac number, because 91651287 - 2¹⁵ = 91618519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91651237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167587 + ... + 168132.

It is an arithmetic number, because the mean of its divisors is an integer number (9400160).

Almost surely, 2^91651287 is an apocalyptic number.

91651287 is a deficient number, since it is larger than the sum of its proper divisors (58751273).

91651287 is a wasteful number, since it uses less digits than its factorization.

91651287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335742.

The product of its digits is 30240, while the sum is 39.

The square root of 91651287 is about 9573.4678669749. The cubic root of 91651287 is about 450.8646535945.

The spelling of 91651287 in words is "ninety-one million, six hundred fifty-one thousand, two hundred eighty-seven".