21478346 has 4 divisors (see below), whose sum is σ = 32217522. Its totient is φ = 10739172.

The previous prime is 21478339. The next prime is 21478351. The reversal of 21478346 is 64387412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13039321 + 8439025 = 3611^2 + 2905^2 .

It is a super-2 number, since 2×21478346² = 922638693791432, which contains 22 as substring.

It is a plaindrome in base 11.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5369585 + ... + 5369588.

Almost surely, 2^21478346 is an apocalyptic number.

21478346 is a deficient number, since it is larger than the sum of its proper divisors (10739176).

21478346 is a wasteful number, since it uses less digits than its factorization.

21478346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10739175.

The product of its digits is 32256, while the sum is 35.

The square root of 21478346 is about 4634.4736486466. The cubic root of 21478346 is about 277.9715047653.

The spelling of 21478346 in words is "twenty-one million, four hundred seventy-eight thousand, three hundred forty-six".