21036351 has 16 divisors (see below), whose sum is σ = 32168448. Its totient is φ = 11978400.

The previous prime is 21036347. The next prime is 21036371. The reversal of 21036351 is 15363012.

It is not a de Polignac number, because 21036351 - 2² = 21036347 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21036311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4921 + ... + 8141.

It is an arithmetic number, because the mean of its divisors is an integer number (2010528).

Almost surely, 2^21036351 is an apocalyptic number.

21036351 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21036351 is a deficient number, since it is larger than the sum of its proper divisors (11132097).

21036351 is a wasteful number, since it uses less digits than its factorization.

21036351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3542.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 21036351 is about 4586.5401993224. The cubic root of 21036351 is about 276.0515157987.

Adding to 21036351 its reverse (15363012), we get a palindrome (36399363).

It can be divided in two parts, 2 and 1036351, that multiplied together give a palindrome (2072702).

The spelling of 21036351 in words is "twenty-one million, thirty-six thousand, three hundred fifty-one".