21498747 has 8 divisors (see below), whose sum is σ = 30173760. Its totient is φ = 13578120.

The previous prime is 21498733. The next prime is 21498793. The reversal of 21498747 is 74789412.

It is a happy number.

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

It is not a de Polignac number, because 21498747 - 2⁶ = 21498683 is a prime.

It is a super-2 number, since 2×21498747² = 924392245140018, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21498699 and 21498708.

It is not an unprimeable number, because it can be changed into a prime (21498707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188529 + ... + 188642.

It is an arithmetic number, because the mean of its divisors is an integer number (3771720).

Almost surely, 2^21498747 is an apocalyptic number.

21498747 is a deficient number, since it is larger than the sum of its proper divisors (8675013).

21498747 is a wasteful number, since it uses less digits than its factorization.

21498747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377193.

The product of its digits is 112896, while the sum is 42.

The square root of 21498747 is about 4636.6741313144. The cubic root of 21498747 is about 278.0594864334.

The spelling of 21498747 in words is "twenty-one million, four hundred ninety-eight thousand, seven hundred forty-seven".