21238377 has 4 divisors (see below), whose sum is σ = 28317840. Its totient is φ = 14158916.

The previous prime is 21238363. The next prime is 21238429. The reversal of 21238377 is 77383212.

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 21238377 - 2⁷ = 21238249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21238307) 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, 3539727 + ... + 3539732.

It is an arithmetic number, because the mean of its divisors is an integer number (7079460).

Almost surely, 2^21238377 is an apocalyptic number.

It is an amenable number.

21238377 is a deficient number, since it is larger than the sum of its proper divisors (7079463).

21238377 is an equidigital number, since it uses as much as digits as its factorization.

21238377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7079462.

The product of its digits is 14112, while the sum is 33.

The square root of 21238377 is about 4608.5113648553. The cubic root of 21238377 is about 276.9324036685.

The spelling of 21238377 in words is "twenty-one million, two hundred thirty-eight thousand, three hundred seventy-seven".