21142619 has 4 divisors (see below), whose sum is σ = 21225144. Its totient is φ = 21060096.

The previous prime is 21142613. The next prime is 21142643. The reversal of 21142619 is 91624112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21142619 is a prime.

It is a super-2 number, since 2×21142619² = 894020676358322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21142613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40877 + ... + 41390.

It is an arithmetic number, because the mean of its divisors is an integer number (5306286).

Almost surely, 2^21142619 is an apocalyptic number.

21142619 is a deficient number, since it is larger than the sum of its proper divisors (82525).

21142619 is an equidigital number, since it uses as much as digits as its factorization.

21142619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82524.

The product of its digits is 864, while the sum is 26.

The square root of 21142619 is about 4598.1103727510. The cubic root of 21142619 is about 276.5155725691.

The spelling of 21142619 in words is "twenty-one million, one hundred forty-two thousand, six hundred nineteen".