21019427 has 8 divisors (see below), whose sum is σ = 24694320. Its totient is φ = 17638560.

The previous prime is 21019409. The next prime is 21019459. The reversal of 21019427 is 72491012.

21019427 = T₇₃ + T₇₄ + ... + T₅₀₁.

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

It is a cyclic number.

It is not a de Polignac number, because 21019427 - 2⁶ = 21019363 is a prime.

It is a super-2 number, since 2×21019427² = 883632622816658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21019396 and 21019405.

It is not an unprimeable number, because it can be changed into a prime (21019487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73352 + ... + 73637.

It is an arithmetic number, because the mean of its divisors is an integer number (3086790).

Almost surely, 2^21019427 is an apocalyptic number.

21019427 is a deficient number, since it is larger than the sum of its proper divisors (3674893).

21019427 is a wasteful number, since it uses less digits than its factorization.

21019427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147013.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21019427 is about 4584.6948644375. The cubic root of 21019427 is about 275.9774670045.

The spelling of 21019427 in words is "twenty-one million, nineteen thousand, four hundred twenty-seven".