20526991 has 8 divisors (see below), whose sum is σ = 21507584. Its totient is φ = 19566360.

The previous prime is 20526977. The next prime is 20526997. The reversal of 20526991 is 19962502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20526991 - 2⁵ = 20526959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20526997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2865 + ... + 7018.

It is an arithmetic number, because the mean of its divisors is an integer number (2688448).

Almost surely, 2^20526991 is an apocalyptic number.

20526991 is a deficient number, since it is larger than the sum of its proper divisors (980593).

20526991 is an equidigital number, since it uses as much as digits as its factorization.

20526991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9981.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 20526991 is about 4530.6722459255. The cubic root of 20526991 is about 273.8052454823.

The spelling of 20526991 in words is "twenty million, five hundred twenty-six thousand, nine hundred ninety-one".