21516034 has 4 divisors (see below), whose sum is σ = 32274054. Its totient is φ = 10758016.

The previous prime is 21516029. The next prime is 21516041. The reversal of 21516034 is 43061512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16785409 + 4730625 = 4097^2 + 2175^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21515996 and 21516014.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5379007 + ... + 5379010.

Almost surely, 2^21516034 is an apocalyptic number.

21516034 is a deficient number, since it is larger than the sum of its proper divisors (10758020).

21516034 is a wasteful number, since it uses less digits than its factorization.

21516034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10758019.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21516034 is about 4638.5379161973. The cubic root of 21516034 is about 278.1339950632.

Adding to 21516034 its reverse (43061512), we get a palindrome (64577546).

The spelling of 21516034 in words is "twenty-one million, five hundred sixteen thousand, thirty-four".