21887801 has 8 divisors (see below), whose sum is σ = 23636424. Its totient is φ = 20148480.

The previous prime is 21887797. The next prime is 21887807. The reversal of 21887801 is 10878812.

It can be written as a sum of positive squares in 4 ways, for example, as 7295401 + 14592400 = 2701^2 + 3820^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21887801 - 2² = 21887797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21887807) 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, 3041 + ... + 7281.

It is an arithmetic number, because the mean of its divisors is an integer number (2954553).

Almost surely, 2^21887801 is an apocalyptic number.

It is an amenable number.

21887801 is a deficient number, since it is larger than the sum of its proper divisors (1748623).

21887801 is a wasteful number, since it uses less digits than its factorization.

21887801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4651.

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 21887801 is about 4678.4400177837. The cubic root of 21887801 is about 279.7267785477.

The spelling of 21887801 in words is "twenty-one million, eight hundred eighty-seven thousand, eight hundred one".