21436490 has 16 divisors (see below), whose sum is σ = 40855752. Its totient is φ = 8070144.

The previous prime is 21436453. The next prime is 21436501. The reversal of 21436490 is 9463412.

It can be written as a sum of positive squares in 4 ways, for example, as 18515809 + 2920681 = 4303^2 + 1709^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62879 + ... + 63218.

Almost surely, 2^21436490 is an apocalyptic number.

21436490 is a deficient number, since it is larger than the sum of its proper divisors (19419262).

21436490 is a wasteful number, since it uses less digits than its factorization.

21436490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126121.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21436490 is about 4629.9557233304. The cubic root of 21436490 is about 277.7908213727.

The spelling of 21436490 in words is "twenty-one million, four hundred thirty-six thousand, four hundred ninety".