20291616 has 36 divisors (see below), whose sum is σ = 57705102. Its totient is φ = 6763776.

The previous prime is 20291611. The next prime is 20291653. The reversal of 20291616 is 61619202.

20291616 is a `hidden beast` number, since 20 + 29 + 1 + 616 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 41616 = 4500^2 + 204^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20291616.

It is not an unprimeable number, because it can be changed into a prime (20291611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34941 + ... + 35516.

Almost surely, 2^20291616 is an apocalyptic number.

It is an amenable number.

20291616 is an abundant number, since it is smaller than the sum of its proper divisors (37413486).

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

20291616 is a wasteful number, since it uses less digits than its factorization.

20291616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70473 (or 70462 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 20291616 is about 4504.6216267296. The cubic root of 20291616 is about 272.7546803971.

The spelling of 20291616 in words is "twenty million, two hundred ninety-one thousand, six hundred sixteen".