21396488 has 8 divisors (see below), whose sum is σ = 40118430. Its totient is φ = 10698240.

The previous prime is 21396481. The next prime is 21396493. The reversal of 21396488 is 88469312.

It can be written as a sum of positive squares in only one way, i.e., 12264004 + 9132484 = 3502^2 + 3022^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21396481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1337273 + ... + 1337288.

Almost surely, 2^21396488 is an apocalyptic number.

It is an amenable number.

21396488 is a deficient number, since it is larger than the sum of its proper divisors (18721942).

21396488 is a wasteful number, since it uses less digits than its factorization.

21396488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2674567 (or 2674563 counting only the distinct ones).

The product of its digits is 82944, while the sum is 41.

The square root of 21396488 is about 4625.6337944113. The cubic root of 21396488 is about 277.6179213682.

The spelling of 21396488 in words is "twenty-one million, three hundred ninety-six thousand, four hundred eighty-eight".