21019682 has 4 divisors (see below), whose sum is σ = 31529526. Its totient is φ = 10509840.

The previous prime is 21019657. The next prime is 21019699. The reversal of 21019682 is 28691012.

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

It can be written as a sum of positive squares in only one way, i.e., 20967241 + 52441 = 4579^2 + 229^2 .

It is a super-2 number, since 2×21019682² = 883654062762248, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5254919 + ... + 5254922.

Almost surely, 2^21019682 is an apocalyptic number.

21019682 is a deficient number, since it is larger than the sum of its proper divisors (10509844).

21019682 is a wasteful number, since it uses less digits than its factorization.

21019682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10509843.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 21019682 is about 4584.7226742738. The cubic root of 21019682 is about 275.9785830192.

The spelling of 21019682 in words is "twenty-one million, nineteen thousand, six hundred eighty-two".