21096490 has 16 divisors (see below), whose sum is σ = 40207752. Its totient is φ = 7942144.

The previous prime is 21096487. The next prime is 21096499. The reversal of 21096490 is 9469012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16313521 + 4782969 = 4039^2 + 2187^2 .

It is not an unprimeable number, because it can be changed into a prime (21096499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61879 + ... + 62218.

Almost surely, 2^21096490 is an apocalyptic number.

21096490 is a deficient number, since it is larger than the sum of its proper divisors (19111262).

21096490 is a wasteful number, since it uses less digits than its factorization.

21096490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124121.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 21096490 is about 4593.0915514499. The cubic root of 21096490 is about 276.3143254312.

The spelling of 21096490 in words is "twenty-one million, ninety-six thousand, four hundred ninety".