21426570 has 96 divisors (see below), whose sum is σ = 63483264. Its totient is φ = 4963200.

The previous prime is 21426553. The next prime is 21426583. The reversal of 21426570 is 7562412.

21426570 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 657 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22300 + ... + 23240.

It is an arithmetic number, because the mean of its divisors is an integer number (661284).

Almost surely, 2^21426570 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21426570, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31741632).

21426570 is an abundant number, since it is smaller than the sum of its proper divisors (42056694).

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

21426570 is a wasteful number, since it uses less digits than its factorization.

21426570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988 (or 985 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21426570 is about 4628.8843148214. The cubic root of 21426570 is about 277.7479643855.

Adding to 21426570 its reverse (7562412), we get a palindrome (28988982).

The spelling of 21426570 in words is "twenty-one million, four hundred twenty-six thousand, five hundred seventy".