21498087 has 8 divisors (see below), whose sum is σ = 30869104. Its totient is φ = 13229568.

The previous prime is 21498083. The next prime is 21498091. The reversal of 21498087 is 78089412.

It is an interprime number because it is at equal distance from previous prime (21498083) and next prime (21498091).

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

It is not a de Polignac number, because 21498087 - 2² = 21498083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 551233 = 21498087 / (2 + 1 + 4 + 9 + 8 + 0 + 8 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21498083) 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, 275578 + ... + 275655.

It is an arithmetic number, because the mean of its divisors is an integer number (3858638).

Almost surely, 2^21498087 is an apocalyptic number.

21498087 is a deficient number, since it is larger than the sum of its proper divisors (9371017).

21498087 is a wasteful number, since it uses less digits than its factorization.

21498087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551249.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 21498087 is about 4636.6029590639. The cubic root of 21498087 is about 278.0566409786.

The spelling of 21498087 in words is "twenty-one million, four hundred ninety-eight thousand, eighty-seven".