21522236 has 6 divisors (see below), whose sum is σ = 37663920. Its totient is φ = 10761116.

The previous prime is 21522223. The next prime is 21522251. The reversal of 21522236 is 63222512.

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, 2690276 + ... + 2690283.

It is an arithmetic number, because the mean of its divisors is an integer number (6277320).

Almost surely, 2^21522236 is an apocalyptic number.

It is an amenable number.

21522236 is a deficient number, since it is larger than the sum of its proper divisors (16141684).

21522236 is a wasteful number, since it uses less digits than its factorization.

21522236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5380563 (or 5380561 counting only the distinct ones).

The product of its digits is 1440, while the sum is 23.

The square root of 21522236 is about 4639.2063976504. The cubic root of 21522236 is about 278.1607165510.

Adding to 21522236 its reverse (63222512), we get a palindrome (84744748).

The spelling of 21522236 in words is "twenty-one million, five hundred twenty-two thousand, two hundred thirty-six".