20515516 has 48 divisors (see below), whose sum is σ = 44128000. Its totient is φ = 8319024.

The previous prime is 20515511. The next prime is 20515531. The reversal of 20515516 is 61551502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20515511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25675 + ... + 26461.

Almost surely, 2^20515516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20515516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22064000).

20515516 is an abundant number, since it is smaller than the sum of its proper divisors (23612484).

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

20515516 is a wasteful number, since it uses less digits than its factorization.

20515516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 20515516 is about 4529.4057005307. The cubic root of 20515516 is about 273.7542150960.

The spelling of 20515516 in words is "twenty million, five hundred fifteen thousand, five hundred sixteen".