97221819 has 4 divisors (see below), whose sum is σ = 129629096. Its totient is φ = 64814544.

The previous prime is 97221809. The next prime is 97221821. The reversal of 97221819 is 91812279.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 97221819 - 2²⁰ = 96173243 is a prime.

It is a super-2 number, since 2×97221819² = 18904164179337522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a zygodrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (97221809) 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, 16203634 + ... + 16203639.

It is an arithmetic number, because the mean of its divisors is an integer number (32407274).

Almost surely, 2^97221819 is an apocalyptic number.

97221819 is a deficient number, since it is larger than the sum of its proper divisors (32407277).

97221819 is a wasteful number, since it uses less digits than its factorization.

97221819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32407276.

The product of its digits is 18144, while the sum is 39.

The square root of 97221819 is about 9860.1125247129. The cubic root of 97221819 is about 459.8200603715.

It can be divided in two parts, 972 and 21819, that added together give a triangular number (22791 = T₂₁₃).

The spelling of 97221819 in words is "ninety-seven million, two hundred twenty-one thousand, eight hundred nineteen".