21123110658 has 64 divisors (see below), whose sum is σ = 46065801600. Its totient is φ = 6418199040.

The previous prime is 21123110653. The next prime is 21123110663. The reversal of 21123110658 is 85601132112.

It is an interprime number because it is at equal distance from previous prime (21123110653) and next prime (21123110663).

It is a super-2 number, since 2×21123110658² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21123110651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7572328 + ... + 7575116.

It is an arithmetic number, because the mean of its divisors is an integer number (719778150).

Almost surely, 2^21123110658 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123110658, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23032900800).

21123110658 is an abundant number, since it is smaller than the sum of its proper divisors (24942690942).

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

21123110658 is a wasteful number, since it uses less digits than its factorization.

21123110658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3987.

The product of its (nonzero) digits is 2880, while the sum is 30.

The spelling of 21123110658 in words is "twenty-one billion, one hundred twenty-three million, one hundred ten thousand, six hundred fifty-eight".