21765143740 has 24 divisors (see below), whose sum is σ = 45923430672. Its totient is φ = 8664794880.

The previous prime is 21765143723. The next prime is 21765143747. The reversal of 21765143740 is 4734156712.

It is a super-2 number, since 2×21765143740² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21765143693 and 21765143702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765143747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2574589 + ... + 2583028.

It is an arithmetic number, because the mean of its divisors is an integer number (1913476278).

Almost surely, 2^21765143740 is an apocalyptic number.

21765143740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21765143740 is an abundant number, since it is smaller than the sum of its proper divisors (24158286932).

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

21765143740 is a wasteful number, since it uses less digits than its factorization.

21765143740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5157837 (or 5157835 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 40.

The spelling of 21765143740 in words is "twenty-one billion, seven hundred sixty-five million, one hundred forty-three thousand, seven hundred forty".