21500601 has 4 divisors (see below), whose sum is σ = 28667472. Its totient is φ = 14333732.

The previous prime is 21500593. The next prime is 21500621. The reversal of 21500601 is 10600512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21500601 - 2³ = 21500593 is a prime.

It is a super-2 number, since 2×21500601² = 924551686722402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21500621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3583431 + ... + 3583436.

It is an arithmetic number, because the mean of its divisors is an integer number (7166868).

Almost surely, 2^21500601 is an apocalyptic number.

It is an amenable number.

21500601 is a deficient number, since it is larger than the sum of its proper divisors (7166871).

21500601 is an equidigital number, since it uses as much as digits as its factorization.

21500601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7166870.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21500601 is about 4636.8740547917. The cubic root of 21500601 is about 278.0674792631.

The spelling of 21500601 in words is "twenty-one million, five hundred thousand, six hundred one".