21450097 has 4 divisors (see below), whose sum is σ = 21574260. Its totient is φ = 21325936.

The previous prime is 21450083. The next prime is 21450103. The reversal of 21450097 is 79005412.

It is a happy number.

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 13660416 + 7789681 = 3696^2 + 2791^2 .

It is a cyclic number.

It is not a de Polignac number, because 21450097 - 2¹⁵ = 21417329 is a prime.

It is a super-2 number, since 2×21450097² = 920213322618818, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21450797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61822 + ... + 62167.

It is an arithmetic number, because the mean of its divisors is an integer number (5393565).

Almost surely, 2^21450097 is an apocalyptic number.

It is an amenable number.

21450097 is a deficient number, since it is larger than the sum of its proper divisors (124163).

21450097 is a wasteful number, since it uses less digits than its factorization.

21450097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124162.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 21450097 is about 4631.4249427147. The cubic root of 21450097 is about 277.8495856606.

The spelling of 21450097 in words is "twenty-one million, four hundred fifty thousand, ninety-seven".