87219091 has 4 divisors (see below), whose sum is σ = 87610432. Its totient is φ = 86827752.

The previous prime is 87219049. The next prime is 87219103. The reversal of 87219091 is 19091278.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19091278 = 2 ⋅9545639.

It is a cyclic number.

It is not a de Polignac number, because 87219091 - 2¹³ = 87210899 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87219091.

It is not an unprimeable number, because it can be changed into a prime (87219031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195336 + ... + 195781.

It is an arithmetic number, because the mean of its divisors is an integer number (21902608).

Almost surely, 2^87219091 is an apocalyptic number.

87219091 is a deficient number, since it is larger than the sum of its proper divisors (391341).

87219091 is a wasteful number, since it uses less digits than its factorization.

87219091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391340.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 87219091 is about 9339.1161787398. The cubic root of 87219091 is about 443.4764054156.

The spelling of 87219091 in words is "eighty-seven million, two hundred nineteen thousand, ninety-one".