21025434 has 8 divisors (see below), whose sum is σ = 42050880. Its totient is φ = 7008476.

The previous prime is 21025423. The next prime is 21025439. The reversal of 21025434 is 43452012.

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

21025434 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21025434.

It is not an unprimeable number, because it can be changed into a prime (21025439) 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, 1752114 + ... + 1752125.

It is an arithmetic number, because the mean of its divisors is an integer number (5256360).

Almost surely, 2^21025434 is an apocalyptic number.

21025434 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21025434 is a wasteful number, since it uses less digits than its factorization.

21025434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3504244.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21025434 is about 4585.3499321208. The cubic root of 21025434 is about 276.0037544123.

Adding to 21025434 its reverse (43452012), we get a palindrome (64477446).

The spelling of 21025434 in words is "twenty-one million, twenty-five thousand, four hundred thirty-four".