21519106 has 16 divisors (see below), whose sum is σ = 37411200. Its totient is φ = 9092160.

The previous prime is 21519103. The next prime is 21519139. The reversal of 21519106 is 60191512.

It is not an unprimeable number, because it can be changed into a prime (21519101) 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, 9831 + ... + 11818.

It is an arithmetic number, because the mean of its divisors is an integer number (2338200).

Almost surely, 2^21519106 is an apocalyptic number.

21519106 is a deficient number, since it is larger than the sum of its proper divisors (15892094).

21519106 is a wasteful number, since it uses less digits than its factorization.

21519106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21729.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 21519106 is about 4638.8690432044. The cubic root of 21519106 is about 278.1472315015.

It can be divided in two parts, 215 and 19106, that added together give a square (19321 = 139²).

The spelling of 21519106 in words is "twenty-one million, five hundred nineteen thousand, one hundred six".