21190004 has 18 divisors (see below), whose sum is σ = 40761042. Its totient is φ = 9631600.

The previous prime is 21190003. The next prime is 21190051. The reversal of 21190004 is 40009112.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21141604 + 48400 = 4598^2 + 220^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21190003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21407 + ... + 22374.

Almost surely, 2^21190004 is an apocalyptic number.

It is an amenable number.

21190004 is a deficient number, since it is larger than the sum of its proper divisors (19571038).

21190004 is a wasteful number, since it uses less digits than its factorization.

21190004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43807 (or 43794 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21190004 is about 4603.2601490683. The cubic root of 21190004 is about 276.7219947088.

Adding to 21190004 its reverse (40009112), we get a palindrome (61199116).

The spelling of 21190004 in words is "twenty-one million, one hundred ninety thousand, four".