21398652 has 36 divisors (see below), whose sum is σ = 59009496. Its totient is φ = 6484320.

The previous prime is 21398647. The next prime is 21398683. The reversal of 21398652 is 25689312.

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 congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26623 + ... + 27414.

Almost surely, 2^21398652 is an apocalyptic number.

21398652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21398652 is an abundant number, since it is smaller than the sum of its proper divisors (37610844).

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

21398652 is a wasteful number, since it uses less digits than its factorization.

21398652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54058 (or 54053 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21398652 is about 4625.8677023884. The cubic root of 21398652 is about 277.6272803017.

The spelling of 21398652 in words is "twenty-one million, three hundred ninety-eight thousand, six hundred fifty-two".