21389374 has 8 divisors (see below), whose sum is σ = 32270040. Its totient is φ = 10632696.

The previous prime is 21389363. The next prime is 21389377. The reversal of 21389374 is 47398312.

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

It is a super-2 number, since 2×21389374² = 915010640223752, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21389377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30564 + ... + 31255.

It is an arithmetic number, because the mean of its divisors is an integer number (4033755).

Almost surely, 2^21389374 is an apocalyptic number.

21389374 is a deficient number, since it is larger than the sum of its proper divisors (10880666).

21389374 is a wasteful number, since it uses less digits than its factorization.

21389374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61994.

The product of its digits is 36288, while the sum is 37.

The square root of 21389374 is about 4624.8647547793. The cubic root of 21389374 is about 277.5871500750.

The spelling of 21389374 in words is "twenty-one million, three hundred eighty-nine thousand, three hundred seventy-four".