20787345 has 48 divisors (see below), whose sum is σ = 39508560. Its totient is φ = 10063872.

The previous prime is 20787337. The next prime is 20787373. The reversal of 20787345 is 54378702.

It can be written as a sum of positive squares in 8 ways, for example, as 725904 + 20061441 = 852^2 + 4479^2 .

It is not a de Polignac number, because 20787345 - 2³ = 20787337 is a prime.

It is a super-2 number, since 2×20787345² = 864227424298050, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21717 + ... + 22653.

It is an arithmetic number, because the mean of its divisors is an integer number (823095).

Almost surely, 2^20787345 is an apocalyptic number.

It is an amenable number.

20787345 is a deficient number, since it is larger than the sum of its proper divisors (18721215).

20787345 is a wasteful number, since it uses less digits than its factorization.

20787345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994 (or 991 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 20787345 is about 4559.3140931504. The cubic root of 20787345 is about 274.9579880725.

The spelling of 20787345 in words is "twenty million, seven hundred eighty-seven thousand, three hundred forty-five".