21718061000 has 96 divisors (see below), whose sum is σ = 53986257000. Its totient is φ = 8176102400.

The previous prime is 21718060997. The next prime is 21718061009. The reversal of 21718061000 is 16081712.

It can be written as a sum of positive squares in 12 ways, for example, as 1337072356 + 20380988644 = 36566^2 + 142762^2 .

It is not an unprimeable number, because it can be changed into a prime (21718061009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251426 + ... + 326574.

Almost surely, 2^21718061000 is an apocalyptic number.

21718061000 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 21718061000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26993128500).

21718061000 is an abundant number, since it is smaller than the sum of its proper divisors (32268196000).

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

21718061000 is a wasteful number, since it uses less digits than its factorization.

21718061000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75204 (or 75173 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 26.

The spelling of 21718061000 in words is "twenty-one billion, seven hundred eighteen million, sixty-one thousand".