21572067 has 16 divisors (see below), whose sum is σ = 31455360. Its totient is φ = 13041600.

The previous prime is 21572059. The next prime is 21572069. The reversal of 21572067 is 76027512.

It is not a de Polignac number, because 21572067 - 2³ = 21572059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21572069) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24684 + ... + 25542.

It is an arithmetic number, because the mean of its divisors is an integer number (1965960).

Almost surely, 2^21572067 is an apocalyptic number.

21572067 is a deficient number, since it is larger than the sum of its proper divisors (9883293).

21572067 is a wasteful number, since it uses less digits than its factorization.

21572067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1634.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21572067 is about 4644.5739309435. The cubic root of 21572067 is about 278.3752286926.

Adding to 21572067 its reverse (76027512), we get a palindrome (97599579).

Subtracting 21572067 from its reverse (76027512), we obtain a palindrome (54455445).

It can be divided in two parts, 2157 and 2067, that added together give a palindrome (4224).

The spelling of 21572067 in words is "twenty-one million, five hundred seventy-two thousand, sixty-seven".