21138355674 has 48 divisors (see below), whose sum is σ = 47589927840. Its totient is φ = 7032193200.

The previous prime is 21138355669. The next prime is 21138355729. The reversal of 21138355674 is 47655383112.

It is a happy number.

21138355674 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 83 + 5 + 567 + 4 = 666.

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, 204649 + ... + 290099.

It is an arithmetic number, because the mean of its divisors is an integer number (991456830).

Almost surely, 2^21138355674 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21138355674, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23794963920).

21138355674 is an abundant number, since it is smaller than the sum of its proper divisors (26451572166).

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

21138355674 is an equidigital number, since it uses as much as digits as its factorization.

21138355674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85977 (or 85965 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 21138355674 in words is "twenty-one billion, one hundred thirty-eight million, three hundred fifty-five thousand, six hundred seventy-four".