21471011 has 4 divisors (see below), whose sum is σ = 21486024. Its totient is φ = 21456000.

The previous prime is 21470987. The next prime is 21471019. The reversal of 21471011 is 11017412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21471011 - 2⁶ = 21470947 is a prime.

It is a super-2 number, since 2×21471011² = 922008626724242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21471019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5105 + ... + 8306.

It is an arithmetic number, because the mean of its divisors is an integer number (5371506).

Almost surely, 2^21471011 is an apocalyptic number.

21471011 is a deficient number, since it is larger than the sum of its proper divisors (15013).

21471011 is a wasteful number, since it uses less digits than its factorization.

21471011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15012.

The product of its (nonzero) digits is 56, while the sum is 17.

The square root of 21471011 is about 4633.6822290701. The cubic root of 21471011 is about 277.9398581147.

Adding to 21471011 its reverse (11017412), we get a palindrome (32488423).

The spelling of 21471011 in words is "twenty-one million, four hundred seventy-one thousand, eleven".