21247426 has 8 divisors (see below), whose sum is σ = 31914000. Its totient is φ = 10609428.

The previous prime is 21247411. The next prime is 21247439. The reversal of 21247426 is 62474212.

It is a happy number.

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

It is a super-2 number, since 2×21247426² = 902906223250952, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21247394 and 21247403.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5176 + ... + 8323.

It is an arithmetic number, because the mean of its divisors is an integer number (3989250).

Almost surely, 2^21247426 is an apocalyptic number.

21247426 is a deficient number, since it is larger than the sum of its proper divisors (10666574).

21247426 is a wasteful number, since it uses less digits than its factorization.

21247426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14288.

The product of its digits is 5376, while the sum is 28.

The square root of 21247426 is about 4609.4930306922. The cubic root of 21247426 is about 276.9717287937.

The spelling of 21247426 in words is "twenty-one million, two hundred forty-seven thousand, four hundred twenty-six".