21117735100 has 72 divisors (see below), whose sum is σ = 57133093248. Its totient is φ = 6582148800.

The previous prime is 21117735097. The next prime is 21117735103. The reversal of 21117735100 is 153771112.

It is an interprime number because it is at equal distance from previous prime (21117735097) and next prime (21117735103).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117735103) 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, 1363582 + ... + 1378981.

It is an arithmetic number, because the mean of its divisors is an integer number (793515184).

Almost surely, 2^21117735100 is an apocalyptic number.

21117735100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21117735100 is an abundant number, since it is smaller than the sum of its proper divisors (36015358148).

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

21117735100 is a wasteful number, since it uses less digits than its factorization.

21117735100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742595 (or 2742588 counting only the distinct ones).

The product of its (nonzero) digits is 1470, while the sum is 28.

The spelling of 21117735100 in words is "twenty-one billion, one hundred seventeen million, seven hundred thirty-five thousand, one hundred".