21752516 has 6 divisors (see below), whose sum is σ = 38066910. Its totient is φ = 10876256.

The previous prime is 21752461. The next prime is 21752519. The reversal of 21752516 is 61525712.

It can be written as a sum of positive squares in only one way, i.e., 16370116 + 5382400 = 4046^2 + 2320^2 .

It is not an unprimeable number, because it can be changed into a prime (21752519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2719061 + ... + 2719068.

It is an arithmetic number, because the mean of its divisors is an integer number (6344485).

Almost surely, 2^21752516 is an apocalyptic number.

It is an amenable number.

21752516 is a deficient number, since it is larger than the sum of its proper divisors (16314394).

21752516 is a wasteful number, since it uses less digits than its factorization.

21752516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5438133 (or 5438131 counting only the distinct ones).

The product of its digits is 4200, while the sum is 29.

The square root of 21752516 is about 4663.9592622578. The cubic root of 21752516 is about 279.1492715777.

The spelling of 21752516 in words is "twenty-one million, seven hundred fifty-two thousand, five hundred sixteen".