21011019 has 8 divisors (see below), whose sum is σ = 28040592. Its totient is φ = 13994400.

The previous prime is 21011009. The next prime is 21011033. The reversal of 21011019 is 91011012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21011019 - 2⁵ = 21010987 is a prime.

It is a super-2 number, since 2×21011019² = 882925838836722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21010989 and 21011007.

It is not an unprimeable number, because it can be changed into a prime (21011009) 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, 1569 + ... + 6669.

It is an arithmetic number, because the mean of its divisors is an integer number (3505074).

Almost surely, 2^21011019 is an apocalyptic number.

21011019 is a deficient number, since it is larger than the sum of its proper divisors (7029573).

21011019 is a wasteful number, since it uses less digits than its factorization.

21011019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6477.

The product of its (nonzero) digits is 18, while the sum is 15.

The square root of 21011019 is about 4583.7778087512. Note that the first 3 decimals coincide. The cubic root of 21011019 is about 275.9406640982.

The spelling of 21011019 in words is "twenty-one million, eleven thousand, nineteen".