21420296 has 24 divisors (see below), whose sum is σ = 42393870. Its totient is φ = 10145088.

The previous prime is 21420293. The next prime is 21420331. The reversal of 21420296 is 69202412.

It can be written as a sum of positive squares in only one way, i.e., 15319396 + 6100900 = 3914^2 + 2470^2 .

It is not an unprimeable number, because it can be changed into a prime (21420293) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 821 + ... + 6596.

Almost surely, 2^21420296 is an apocalyptic number.

It is an amenable number.

21420296 is a deficient number, since it is larger than the sum of its proper divisors (20973574).

21420296 is a wasteful number, since it uses less digits than its factorization.

21420296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7461 (or 7438 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21420296 is about 4628.2065641023. The cubic root of 21420296 is about 277.7208522401.

The spelling of 21420296 in words is "twenty-one million, four hundred twenty thousand, two hundred ninety-six".