91521419 has 16 divisors (see below), whose sum is σ = 103753440. Its totient is φ = 79968000.

The previous prime is 91521413. The next prime is 91521427. The reversal of 91521419 is 91412519.

It is a cyclic number.

It is not a de Polignac number, because 91521419 - 2¹² = 91517323 is a prime.

It is a super-2 number, since 2×91521419² = 16752340271547122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91521413) 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, 89129 + ... + 90149.

It is an arithmetic number, because the mean of its divisors is an integer number (6484590).

Almost surely, 2^91521419 is an apocalyptic number.

91521419 is a deficient number, since it is larger than the sum of its proper divisors (12232021).

91521419 is a wasteful number, since it uses less digits than its factorization.

91521419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342.

The product of its digits is 3240, while the sum is 32.

The square root of 91521419 is about 9566.6827584069. The cubic root of 91521419 is about 450.6515975985.

Subtracting from 91521419 its reverse (91412519), we obtain a square (108900 = 330²).

The spelling of 91521419 in words is "ninety-one million, five hundred twenty-one thousand, four hundred nineteen".