20421867 has 8 divisors (see below), whose sum is σ = 27291600. Its totient is φ = 13583360.

The previous prime is 20421859. The next prime is 20421871. The reversal of 20421867 is 76812402.

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 20421867 - 2³ = 20421859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20421367) 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, 6234 + ... + 8927.

It is an arithmetic number, because the mean of its divisors is an integer number (3411450).

Almost surely, 2^20421867 is an apocalyptic number.

20421867 is a deficient number, since it is larger than the sum of its proper divisors (6869733).

20421867 is a wasteful number, since it uses less digits than its factorization.

20421867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15613.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20421867 is about 4519.0559854908. The cubic root of 20421867 is about 273.3370362708.

The spelling of 20421867 in words is "twenty million, four hundred twenty-one thousand, eight hundred sixty-seven".