21542067 has 24 divisors (see below), whose sum is σ = 32947200. Its totient is φ = 13525488.

The previous prime is 21542063. The next prime is 21542071. The reversal of 21542067 is 76024512.

It is an interprime number because it is at equal distance from previous prime (21542063) and next prime (21542071).

It is not a de Polignac number, because 21542067 - 2² = 21542063 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21542067.

It is not an unprimeable number, because it can be changed into a prime (21542063) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44734 + ... + 45212.

It is an arithmetic number, because the mean of its divisors is an integer number (1372800).

Almost surely, 2^21542067 is an apocalyptic number.

21542067 is a deficient number, since it is larger than the sum of its proper divisors (11405133).

21542067 is a wasteful number, since it uses less digits than its factorization.

21542067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767 (or 764 counting only the distinct ones).

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

The square root of 21542067 is about 4641.3432322982. The cubic root of 21542067 is about 278.2461245262.

Adding to 21542067 its reverse (76024512), we get a palindrome (97566579).

The spelling of 21542067 in words is "twenty-one million, five hundred forty-two thousand, sixty-seven".