21039877 has 8 divisors (see below), whose sum is σ = 21903840. Its totient is φ = 20185200.

The previous prime is 21039869. The next prime is 21039881. The reversal of 21039877 is 77893012.

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 21039877 - 2³ = 21039869 is a prime.

It is a super-3 number, since 3×21039877³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21039817) 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, 2502 + ... + 6952.

It is an arithmetic number, because the mean of its divisors is an integer number (2737980).

Almost surely, 2^21039877 is an apocalyptic number.

It is an amenable number.

21039877 is a deficient number, since it is larger than the sum of its proper divisors (863963).

21039877 is a wasteful number, since it uses less digits than its factorization.

21039877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4643.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21039877 is about 4586.9245688151. The cubic root of 21039877 is about 276.0669383605.

The spelling of 21039877 in words is "twenty-one million, thirty-nine thousand, eight hundred seventy-seven".