21500241 has 8 divisors (see below), whose sum is σ = 32762304. Its totient is φ = 12285840.

The previous prime is 21500231. The next prime is 21500251. The reversal of 21500241 is 14200512.

It is an interprime number because it is at equal distance from previous prime (21500231) and next prime (21500251).

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

It is not a de Polignac number, because 21500241 - 2⁵ = 21500209 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21500241.

It is not an unprimeable number, because it can be changed into a prime (21500231) 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, 511890 + ... + 511931.

It is an arithmetic number, because the mean of its divisors is an integer number (4095288).

Almost surely, 2^21500241 is an apocalyptic number.

21500241 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21500241 is a deficient number, since it is larger than the sum of its proper divisors (11262063).

21500241 is a wasteful number, since it uses less digits than its factorization.

21500241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023831.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21500241 is about 4636.8352353734. The cubic root of 21500241 is about 278.0659272933.

Adding to 21500241 its reverse (14200512), we get a palindrome (35700753).

The spelling of 21500241 in words is "twenty-one million, five hundred thousand, two hundred forty-one".