20147543640 has 384 divisors, whose sum is σ = 78434827200. Its totient is φ = 4586803200.

The previous prime is 20147543599. The next prime is 20147543641. The reversal of 20147543640 is 4634574102.

20147543640 is a `hidden beast` number, since 2 + 0 + 1 + 4 + 7 + 5 + 4 + 3 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20147543595 and 20147543604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20147543641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16775040 + ... + 16776240.

Almost surely, 2^20147543640 is an apocalyptic number.

20147543640 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 20147543640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39217413600).

20147543640 is an abundant number, since it is smaller than the sum of its proper divisors (58287283560).

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

20147543640 is a wasteful number, since it uses less digits than its factorization.

20147543640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1552 (or 1535 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 20147543640 in words is "twenty billion, one hundred forty-seven million, five hundred forty-three thousand, six hundred forty".