21320296 has 8 divisors (see below), whose sum is σ = 39975570. Its totient is φ = 10660144.

The previous prime is 21320267. The next prime is 21320297. The reversal of 21320296 is 69202312.

It is a happy number.

21320296 is nontrivially palindromic in base 15.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 617796 = 4550^2 + 786^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21320296.

It is not an unprimeable number, because it can be changed into a prime (21320297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332511 + ... + 1332526.

Almost surely, 2^21320296 is an apocalyptic number.

It is an amenable number.

21320296 is a deficient number, since it is larger than the sum of its proper divisors (18655274).

21320296 is a wasteful number, since it uses less digits than its factorization.

21320296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2665043 (or 2665039 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21320296 is about 4617.3906050929. The cubic root of 21320296 is about 277.2880008395.

The spelling of 21320296 in words is "twenty-one million, three hundred twenty thousand, two hundred ninety-six".