21375123501156 has 24 divisors (see below), whose sum is σ = 49904472119040. Its totient is φ = 7120872031392.

The previous prime is 21375123501143. The next prime is 21375123501157. The reversal of 21375123501156 is 65110532157312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21375123501157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521120596 + ... + 521161611.

It is an arithmetic number, because the mean of its divisors is an integer number (2079353004960).

Almost surely, 2^{21375123501156} is an apocalyptic number.

It is an amenable number.

21375123501156 is an abundant number, since it is smaller than the sum of its proper divisors (28529348617884).

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

21375123501156 is a wasteful number, since it uses less digits than its factorization.

21375123501156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042283923 (or 1042283921 counting only the distinct ones).

The product of its (nonzero) digits is 189000, while the sum is 42.

Adding to 21375123501156 its reverse (65110532157312), we get a palindrome (86485655658468).

The spelling of 21375123501156 in words is "twenty-one trillion, three hundred seventy-five billion, one hundred twenty-three million, five hundred one thousand, one hundred fifty-six".