21192097 has 4 divisors (see below), whose sum is σ = 21224260. Its totient is φ = 21159936.

The previous prime is 21192091. The next prime is 21192113. The reversal of 21192097 is 79029112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9740641 + 11451456 = 3121^2 + 3384^2 .

It is a cyclic number.

It is not a de Polignac number, because 21192097 - 2⁷ = 21191969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21192091) 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, 15072 + ... + 16417.

It is an arithmetic number, because the mean of its divisors is an integer number (5306065).

Almost surely, 2^21192097 is an apocalyptic number.

It is an amenable number.

21192097 is a deficient number, since it is larger than the sum of its proper divisors (32163).

21192097 is an equidigital number, since it uses as much as digits as its factorization.

21192097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32162.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 21192097 is about 4603.4874823334. The cubic root of 21192097 is about 276.7311052949.

The spelling of 21192097 in words is "twenty-one million, one hundred ninety-two thousand, ninety-seven".