20514991 has 4 divisors (see below), whose sum is σ = 23445712. Its totient is φ = 17584272.

The previous prime is 20514979. The next prime is 20515007. The reversal of 20514991 is 19941502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20514991 - 2⁷ = 20514863 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 (20514911) 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, 1465350 + ... + 1465363.

It is an arithmetic number, because the mean of its divisors is an integer number (5861428).

Almost surely, 2^20514991 is an apocalyptic number.

20514991 is a deficient number, since it is larger than the sum of its proper divisors (2930721).

20514991 is an equidigital number, since it uses as much as digits as its factorization.

20514991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2930720.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 20514991 is about 4529.3477455369. The cubic root of 20514991 is about 273.7518799173.

The spelling of 20514991 in words is "twenty million, five hundred fourteen thousand, nine hundred ninety-one".