21420594 has 24 divisors (see below), whose sum is σ = 49981932. Its totient is φ = 6590880.

The previous prime is 21420587. The next prime is 21420643. The reversal of 21420594 is 49502412.

It can be written as a sum of positive squares in 2 ways, for example, as 19474569 + 1946025 = 4413^2 + 1395^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45537 + ... + 46004.

Almost surely, 2^21420594 is an apocalyptic number.

21420594 is an abundant number, since it is smaller than the sum of its proper divisors (28561338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21420594 is a wasteful number, since it uses less digits than its factorization.

21420594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91562 (or 91559 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21420594 is about 4628.2387578862. The cubic root of 21420594 is about 277.7221401220.

The spelling of 21420594 in words is "twenty-one million, four hundred twenty thousand, five hundred ninety-four".