21750513 has 8 divisors (see below), whose sum is σ = 29138976. Its totient is φ = 14431200.

The previous prime is 21750503. The next prime is 21750523. The reversal of 21750513 is 31505712.

It is an interprime number because it is at equal distance from previous prime (21750503) and next prime (21750523).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21750513 - 2⁵ = 21750481 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21750503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16548 + ... + 17813.

It is an arithmetic number, because the mean of its divisors is an integer number (3642372).

Almost surely, 2^21750513 is an apocalyptic number.

It is an amenable number.

21750513 is a deficient number, since it is larger than the sum of its proper divisors (7388463).

21750513 is a wasteful number, since it uses less digits than its factorization.

21750513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34575.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 21750513 is about 4663.7445255931. The cubic root of 21750513 is about 279.1407031719.

The spelling of 21750513 in words is "twenty-one million, seven hundred fifty thousand, five hundred thirteen".