20111534520 has 384 divisors, whose sum is σ = 76945075200. Its totient is φ = 4158336000.

The previous prime is 20111534503. The next prime is 20111534537. The reversal of 20111534520 is 2543511102.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20111534503) and next prime (20111534537).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15457870 + ... + 15459170.

It is an arithmetic number, because the mean of its divisors is an integer number (200377800).

Almost surely, 2^20111534520 is an apocalyptic number.

20111534520 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 20111534520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38472537600).

20111534520 is an abundant number, since it is smaller than the sum of its proper divisors (56833540680).

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

20111534520 is a wasteful number, since it uses less digits than its factorization.

20111534520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1579 (or 1568 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The spelling of 20111534520 in words is "twenty billion, one hundred eleven million, five hundred thirty-four thousand, five hundred twenty".