21521414 has 16 divisors (see below), whose sum is σ = 34774080. Its totient is φ = 9956520.

The previous prime is 21521413. The next prime is 21521419. The reversal of 21521414 is 41412512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4952 + ... + 8219.

It is an arithmetic number, because the mean of its divisors is an integer number (2173380).

Almost surely, 2^21521414 is an apocalyptic number.

21521414 is a deficient number, since it is larger than the sum of its proper divisors (13252666).

21521414 is a wasteful number, since it uses less digits than its factorization.

21521414 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13235.

The product of its digits is 320, while the sum is 20.

The square root of 21521414 is about 4639.1178040658. The cubic root of 21521414 is about 278.1571752365.

Adding to 21521414 its reverse (41412512), we get a palindrome (62933926).

The spelling of 21521414 in words is "twenty-one million, five hundred twenty-one thousand, four hundred fourteen".