21061587077080 has 128 divisors (see below), whose sum is σ = 51768283714560. Its totient is φ = 7648147584000.

The previous prime is 21061587077077. The next prime is 21061587077081. The reversal of 21061587077080 is 8077078516012.

It is a super-2 number, since 2×21061587077080² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061587077081) 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, 2279141260 + ... + 2279150500.

It is an arithmetic number, because the mean of its divisors is an integer number (404439716520).

Almost surely, 2^{21061587077080} is an apocalyptic number.

21061587077080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21061587077080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25884141857280).

21061587077080 is an abundant number, since it is smaller than the sum of its proper divisors (30706696637480).

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

21061587077080 is a wasteful number, since it uses less digits than its factorization.

21061587077080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15881 (or 15877 counting only the distinct ones).

The product of its (nonzero) digits is 1317120, while the sum is 52.

The spelling of 21061587077080 in words is "twenty-one trillion, sixty-one billion, five hundred eighty-seven million, seventy-seven thousand, eighty".