20165996544 has 104 divisors (see below), whose sum is σ = 54508418352. Its totient is φ = 6629621760.

The previous prime is 20165996537. The next prime is 20165996551. The reversal of 20165996544 is 44569956102.

It is an interprime number because it is at equal distance from previous prime (20165996537) and next prime (20165996551).

It is a super-2 number, since 2×20165996544² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 885784 + ... + 908264.

Almost surely, 2^20165996544 is an apocalyptic number.

20165996544 is a gapful number since it is divisible by the number (24) 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 20165996544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27254209176).

20165996544 is an abundant number, since it is smaller than the sum of its proper divisors (34342421808).

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

20165996544 is an equidigital number, since it uses as much as digits as its factorization.

20165996544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22581 (or 22559 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 51.

The spelling of 20165996544 in words is "twenty billion, one hundred sixty-five million, nine hundred ninety-six thousand, five hundred forty-four".