21425019 has 32 divisors (see below), whose sum is σ = 35928576. Its totient is φ = 11032320.

The previous prime is 21425009. The next prime is 21425021. The reversal of 21425019 is 91052412.

It is not a de Polignac number, because 21425019 - 2⁴ = 21425003 is a prime.

It is a super-2 number, since 2×21425019² = 918062878300722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21425019.

It is not an unprimeable number, because it can be changed into a prime (21425009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31309 + ... + 31985.

It is an arithmetic number, because the mean of its divisors is an integer number (1122768).

Almost surely, 2^21425019 is an apocalyptic number.

21425019 is a deficient number, since it is larger than the sum of its proper divisors (14503557).

21425019 is a wasteful number, since it uses less digits than its factorization.

21425019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21425019 is about 4628.7167768184. The cubic root of 21425019 is about 277.7412624653.

The spelling of 21425019 in words is "twenty-one million, four hundred twenty-five thousand, nineteen".