21398548 has 12 divisors (see below), whose sum is σ = 37975392. Its totient is φ = 10548440.

The previous prime is 21398521. The next prime is 21398557. The reversal of 21398548 is 84589312.

It is a self number, because there is not a number n which added to its sum of digits gives 21398548.

It is a congruent number.

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, 37390 + ... + 37957.

It is an arithmetic number, because the mean of its divisors is an integer number (3164616).

Almost surely, 2^21398548 is an apocalyptic number.

It is an amenable number.

21398548 is a deficient number, since it is larger than the sum of its proper divisors (16576844).

21398548 is a wasteful number, since it uses less digits than its factorization.

21398548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75422 (or 75420 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 21398548 is about 4625.8564612404. The cubic root of 21398548 is about 277.6268305338.

The spelling of 21398548 in words is "twenty-one million, three hundred ninety-eight thousand, five hundred forty-eight".