21649442 has 8 divisors (see below), whose sum is σ = 32959056. Its totient is φ = 10663092.

The previous prime is 21649429. The next prime is 21649447. The reversal of 21649442 is 24494612.

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

It is a super-2 number, since 2×21649442² = 937396677822728, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21649399 and 21649408.

It is not an unprimeable number, because it can be changed into a prime (21649447) 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, 80648 + ... + 80915.

It is an arithmetic number, because the mean of its divisors is an integer number (4119882).

Almost surely, 2^21649442 is an apocalyptic number.

21649442 is a deficient number, since it is larger than the sum of its proper divisors (11309614).

21649442 is a wasteful number, since it uses less digits than its factorization.

21649442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161632.

The product of its digits is 13824, while the sum is 32.

The square root of 21649442 is about 4652.8960873847. The cubic root of 21649442 is about 278.7076583116.

The spelling of 21649442 in words is "twenty-one million, six hundred forty-nine thousand, four hundred forty-two".