21025223186 has 128 divisors (see below), whose sum is σ = 38389800960. Its totient is φ = 8530099200.

The previous prime is 21025223171. The next prime is 21025223203. The reversal of 21025223186 is 68132252012.

It is a super-2 number, since 2×21025223186² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 121532996 + ... + 121533168.

It is an arithmetic number, because the mean of its divisors is an integer number (299920320).

Almost surely, 2^21025223186 is an apocalyptic number.

21025223186 is a deficient number, since it is larger than the sum of its proper divisors (17364577774).

21025223186 is a wasteful number, since it uses less digits than its factorization.

21025223186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432.

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 21025223186 its reverse (68132252012), we get a palindrome (89157475198).

The spelling of 21025223186 in words is "twenty-one billion, twenty-five million, two hundred twenty-three thousand, one hundred eighty-six".