20770509 has 4 divisors (see below), whose sum is σ = 27694016. Its totient is φ = 13847004.

The previous prime is 20770499. The next prime is 20770517. The reversal of 20770509 is 90507702.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20770509 - 2¹⁵ = 20737741 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 (20770109) 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, 3461749 + ... + 3461754.

It is an arithmetic number, because the mean of its divisors is an integer number (6923504).

Almost surely, 2^20770509 is an apocalyptic number.

It is an amenable number.

20770509 is a deficient number, since it is larger than the sum of its proper divisors (6923507).

20770509 is an equidigital number, since it uses as much as digits as its factorization.

20770509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6923506.

The product of its (nonzero) digits is 4410, while the sum is 30.

The square root of 20770509 is about 4557.4673888027. The cubic root of 20770509 is about 274.8837370799.

The spelling of 20770509 in words is "twenty million, seven hundred seventy thousand, five hundred nine".