20871763440 has 160 divisors (see below), whose sum is σ = 71270724096. Its totient is φ = 5010631680.

The previous prime is 20871763439. The next prime is 20871763453. The reversal of 20871763440 is 4436717802.

It is a junction number, because it is equal to n+sod(n) for n = 20871763392 and 20871763401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 233542 + ... + 310298.

Almost surely, 2^20871763440 is an apocalyptic number.

20871763440 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 20871763440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35635362048).

20871763440 is an abundant number, since it is smaller than the sum of its proper divisors (50398960656).

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

20871763440 is a wasteful number, since it uses less digits than its factorization.

20871763440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76887 (or 76881 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 42.

The spelling of 20871763440 in words is "twenty billion, eight hundred seventy-one million, seven hundred sixty-three thousand, four hundred forty".