20515520064 has 168 divisors, whose sum is σ = 59373991488. Its totient is φ = 6214855680.

The previous prime is 20515520057. The next prime is 20515520071. The reversal of 20515520064 is 46002551502.

20515520064 = T₄₈₇ + T₄₈₈ + ... + T₄₉₇₅.

It is an interprime number because it is at equal distance from previous prime (20515520057) and next prime (20515520071).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11203629 + ... + 11205459.

It is an arithmetic number, because the mean of its divisors is an integer number (353416616).

Almost surely, 2^20515520064 is an apocalyptic number.

20515520064 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 20515520064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29686995744).

20515520064 is an abundant number, since it is smaller than the sum of its proper divisors (38858471424).

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

20515520064 is a wasteful number, since it uses less digits than its factorization.

20515520064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993 (or 1916 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The spelling of 20515520064 in words is "twenty billion, five hundred fifteen million, five hundred twenty thousand, sixty-four".