21398076 has 36 divisors (see below), whose sum is σ = 61817392. Its totient is φ = 6113664.

The previous prime is 21398063. The next prime is 21398081. The reversal of 21398076 is 67089312.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21398076.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42205 + ... + 42708.

Almost surely, 2^21398076 is an apocalyptic number.

It is an amenable number.

21398076 is an abundant number, since it is smaller than the sum of its proper divisors (40419316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21398076 is a wasteful number, since it uses less digits than its factorization.

21398076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84930 (or 84925 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21398076 is about 4625.8054433796. The cubic root of 21398076 is about 277.6247892609.

It can be divided in two parts, 213 and 98076, that added together give a palindrome (98289).

The spelling of 21398076 in words is "twenty-one million, three hundred ninety-eight thousand, seventy-six".