21727601 has 4 divisors (see below), whose sum is σ = 24831552. Its totient is φ = 18623652.

The previous prime is 21727597. The next prime is 21727609. The reversal of 21727601 is 10672712.

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 21727601 - 2² = 21727597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21727609) 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, 1551965 + ... + 1551978.

It is an arithmetic number, because the mean of its divisors is an integer number (6207888).

Almost surely, 2^21727601 is an apocalyptic number.

It is an amenable number.

21727601 is a deficient number, since it is larger than the sum of its proper divisors (3103951).

21727601 is an equidigital number, since it uses as much as digits as its factorization.

21727601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3103950.

The product of its (nonzero) digits is 1176, while the sum is 26.

The square root of 21727601 is about 4661.2874830888. The cubic root of 21727601 is about 279.0426530885.

The spelling of 21727601 in words is "twenty-one million, seven hundred twenty-seven thousand, six hundred one".