21229516 has 24 divisors (see below), whose sum is σ = 46319616. Its totient is φ = 8271120.

The previous prime is 21229501. The next prime is 21229577. The reversal of 21229516 is 61592212.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34156 + ... + 34771.

It is an arithmetic number, because the mean of its divisors is an integer number (1929984).

Almost surely, 2^21229516 is an apocalyptic number.

It is an amenable number.

21229516 is an abundant number, since it is smaller than the sum of its proper divisors (25090100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21229516 is a wasteful number, since it uses less digits than its factorization.

21229516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68949 (or 68947 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 21229516 is about 4607.5498912112. The cubic root of 21229516 is about 276.8938847275.

The spelling of 21229516 in words is "twenty-one million, two hundred twenty-nine thousand, five hundred sixteen".