20534642550 has 144 divisors (see below), whose sum is σ = 58566764880. Its totient is φ = 5140408320.

The previous prime is 20534642539. The next prime is 20534642563. The reversal of 20534642550 is 5524643502.

20534642550 is a `hidden beast` number, since 2 + 0 + 5 + 3 + 4 + 642 + 5 + 5 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3125569 + ... + 3132131.

It is an arithmetic number, because the mean of its divisors is an integer number (406713645).

Almost surely, 2^20534642550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20534642550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29283382440).

20534642550 is an abundant number, since it is smaller than the sum of its proper divisors (38032122330).

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

20534642550 is a wasteful number, since it uses less digits than its factorization.

20534642550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007 (or 6999 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

The spelling of 20534642550 in words is "twenty billion, five hundred thirty-four million, six hundred forty-two thousand, five hundred fifty".