21063388 has 6 divisors (see below), whose sum is σ = 36860936. Its totient is φ = 10531692.

The previous prime is 21063373. The next prime is 21063403. The reversal of 21063388 is 88336012.

It is an interprime number because it is at equal distance from previous prime (21063373) and next prime (21063403).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2632920 + ... + 2632927.

Almost surely, 2^21063388 is an apocalyptic number.

It is an amenable number.

21063388 is a deficient number, since it is larger than the sum of its proper divisors (15797548).

21063388 is a wasteful number, since it uses less digits than its factorization.

21063388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5265851 (or 5265849 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21063388 is about 4589.4866815364. The cubic root of 21063388 is about 276.1697303690.

The spelling of 21063388 in words is "twenty-one million, sixty-three thousand, three hundred eighty-eight".