820691517 has 16 divisors (see below), whose sum is σ = 1108019520. Its totient is φ = 540262272.

The previous prime is 820691483. The next prime is 820691533. The reversal of 820691517 is 715196028.

820691517 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 820691517 - 2¹⁸ = 820429373 is a prime.

It is a super-2 number, since 2×820691517² = 1347069132151522578, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820691587) 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, 264658 + ... + 267740.

It is an arithmetic number, because the mean of its divisors is an integer number (69251220).

Almost surely, 2^820691517 is an apocalyptic number.

It is an amenable number.

820691517 is a deficient number, since it is larger than the sum of its proper divisors (287328003).

820691517 is a wasteful number, since it uses less digits than its factorization.

820691517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4172.

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 820691517 is about 28647.7139925684. The cubic root of 820691517 is about 936.2531994070.

The spelling of 820691517 in words is "eight hundred twenty million, six hundred ninety-one thousand, five hundred seventeen".