91420561 has 8 divisors (see below), whose sum is σ = 95491584. Its totient is φ = 87357600.

The previous prime is 91420541. The next prime is 91420591. The reversal of 91420561 is 16502419.

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 91420561 - 2²³ = 83031953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91420501) 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, 40320 + ... + 42526.

It is an arithmetic number, because the mean of its divisors is an integer number (11936448).

Almost surely, 2^91420561 is an apocalyptic number.

It is an amenable number.

91420561 is a deficient number, since it is larger than the sum of its proper divisors (4071023).

91420561 is a wasteful number, since it uses less digits than its factorization.

91420561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4031.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 91420561 is about 9561.4099901636. The cubic root of 91420561 is about 450.4859951062.

The spelling of 91420561 in words is "ninety-one million, four hundred twenty thousand, five hundred sixty-one".