10020991 has 4 divisors (see below), whose sum is σ = 10037800. Its totient is φ = 10004184.

The previous prime is 10020977. The next prime is 10021001. The reversal of 10020991 is 19902001.

10020991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19902001 = 7 ⋅2843143.

It is a cyclic number.

It is not a de Polignac number, because 10020991 - 2¹³ = 10012799 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 (10020931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7476 + ... + 8713.

It is an arithmetic number, because the mean of its divisors is an integer number (2509450).

Almost surely, 2^10020991 is an apocalyptic number.

10020991 is a deficient number, since it is larger than the sum of its proper divisors (16809).

10020991 is an equidigital number, since it uses as much as digits as its factorization.

10020991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16808.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 10020991 is about 3165.5948888005. The cubic root of 10020991 is about 215.5941094444.

Adding to 10020991 its reverse (19902001), we get a palindrome (29922992).

It can be divided in two parts, 10020 and 991, that added together give a palindrome (11011).

The spelling of 10020991 in words is "ten million, twenty thousand, nine hundred ninety-one".