21036386 has 12 divisors (see below), whose sum is σ = 36706518. Its totient is φ = 9015552.

The previous prime is 21036371. The next prime is 21036409. The reversal of 21036386 is 68363012.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 14161 = 4585^2 + 119^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 107231 + ... + 107426.

Almost surely, 2^21036386 is an apocalyptic number.

21036386 is a deficient number, since it is larger than the sum of its proper divisors (15670132).

21036386 is a wasteful number, since it uses less digits than its factorization.

21036386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214673 (or 214666 counting only the distinct ones).

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

The square root of 21036386 is about 4586.5440148330. The cubic root of 21036386 is about 276.0516688956.

Adding to 21036386 its reverse (68363012), we get a palindrome (89399398).

The spelling of 21036386 in words is "twenty-one million, thirty-six thousand, three hundred eighty-six".