21430036 has 12 divisors (see below), whose sum is σ = 37592212. Its totient is φ = 10689408.

The previous prime is 21430033. The next prime is 21430037. The reversal of 21430036 is 63003412.

It can be written as a sum of positive squares in 2 ways, for example, as 6220036 + 15210000 = 2494^2 + 3900^2 .

It is a super-2 number, since 2×21430036² = 918492885922592, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21429995 and 21430022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4455 + ... + 7918.

Almost surely, 2^21430036 is an apocalyptic number.

It is an amenable number.

21430036 is a deficient number, since it is larger than the sum of its proper divisors (16162176).

21430036 is a wasteful number, since it uses less digits than its factorization.

21430036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12810 (or 12808 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21430036 is about 4629.2586879543. The cubic root of 21430036 is about 277.7629399126.

Adding to 21430036 its reverse (63003412), we get a palindrome (84433448).

The spelling of 21430036 in words is "twenty-one million, four hundred thirty thousand, thirty-six".