21235123134 has 48 divisors (see below), whose sum is σ = 47939848320. Its totient is φ = 7044793560.

The previous prime is 21235123061. The next prime is 21235123207. The reversal of 21235123134 is 43132153212.

21235123134 is a `hidden beast` number, since 2 + 12 + 3 + 512 + 3 + 134 = 666.

It is an interprime number because it is at equal distance from previous prime (21235123061) and next prime (21235123207).

It is a super-2 number, since 2×21235123134² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21235123098 and 21235123107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 994 + ... + 206085.

It is an arithmetic number, because the mean of its divisors is an integer number (998746840).

Almost surely, 2^21235123134 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21235123134, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23969924160).

21235123134 is an abundant number, since it is smaller than the sum of its proper divisors (26704725186).

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

21235123134 is a wasteful number, since it uses less digits than its factorization.

21235123134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207307 (or 207295 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

Adding to 21235123134 its reverse (43132153212), we get a palindrome (64367276346).

The spelling of 21235123134 in words is "twenty-one billion, two hundred thirty-five million, one hundred twenty-three thousand, one hundred thirty-four".