20697516 has 72 divisors (see below), whose sum is σ = 62409984. Its totient is φ = 5654880.

The previous prime is 20697511. The next prime is 20697559. The reversal of 20697516 is 61579602.

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

It is not an unprimeable number, because it can be changed into a prime (20697511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4011 + ... + 7581.

Almost surely, 2^20697516 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 20697516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31204992).

20697516 is an abundant number, since it is smaller than the sum of its proper divisors (41712468).

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

20697516 is a wasteful number, since it uses less digits than its factorization.

20697516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3611 (or 3606 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20697516 is about 4549.4522747249. The cubic root of 20697516 is about 274.5613546948.

The spelling of 20697516 in words is "twenty million, six hundred ninety-seven thousand, five hundred sixteen".