21379642 has 24 divisors (see below), whose sum is σ = 34835904. Its totient is φ = 9834432.

The previous prime is 21379619. The next prime is 21379663. The reversal of 21379642 is 24697312.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 21379598 and 21379607.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26773 + ... + 27559.

It is an arithmetic number, because the mean of its divisors is an integer number (1451496).

Almost surely, 2^21379642 is an apocalyptic number.

21379642 is a deficient number, since it is larger than the sum of its proper divisors (13456262).

21379642 is a wasteful number, since it uses less digits than its factorization.

21379642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870 (or 853 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 21379642 is about 4623.8124961983. The cubic root of 21379642 is about 277.5450436851.

The spelling of 21379642 in words is "twenty-one million, three hundred seventy-nine thousand, six hundred forty-two".