21134751 has 16 divisors (see below), whose sum is σ = 30907008. Its totient is φ = 12740000.

The previous prime is 21134749. The next prime is 21134753. The reversal of 21134751 is 15743112.

21134751 is a nontrivial binomial coefficient, being equal to C(6502, 2).

It is an interprime number because it is at equal distance from previous prime (21134749) and next prime (21134753).

It is a 5-Lehmer number, since φ(21134751) divides (21134751-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 21134751 - 2¹ = 21134749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21134753) 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, 4876 + ... + 8126.

It is an arithmetic number, because the mean of its divisors is an integer number (1931688).

Almost surely, 2^21134751 is an apocalyptic number.

21134751 is the 6501-st triangular number and also the 3251-st hexagonal number.

21134751 is a deficient number, since it is larger than the sum of its proper divisors (9772257).

21134751 is a wasteful number, since it uses less digits than its factorization.

21134751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3462.

The product of its digits is 840, while the sum is 24.

The square root of 21134751 is about 4597.2547242893. The cubic root of 21134751 is about 276.4812675403.

Adding to 21134751 its reverse (15743112), we get a palindrome (36877863).

The spelling of 21134751 in words is "twenty-one million, one hundred thirty-four thousand, seven hundred fifty-one".