21672450025 has 12 divisors (see below), whose sum is σ = 27252345024. Its totient is φ = 17093762000.

The previous prime is 21672449989. The next prime is 21672450029. The reversal of 21672450025 is 52005427612.

It is a de Polignac number, because none of the positive numbers 2^k-21672450025 is a prime.

It is a super-2 number, since 2×21672450025² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21672450029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6103141 + ... + 6106690.

It is an arithmetic number, because the mean of its divisors is an integer number (2271028752).

Almost surely, 2^21672450025 is an apocalyptic number.

21672450025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21672450025 is a deficient number, since it is larger than the sum of its proper divisors (5579894999).

21672450025 is a wasteful number, since it uses less digits than its factorization.

21672450025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12209912 (or 12209907 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 34.

Adding to 21672450025 its reverse (52005427612), we get a palindrome (73677877637).

The spelling of 21672450025 in words is "twenty-one billion, six hundred seventy-two million, four hundred fifty thousand, twenty-five".