20501857349 has 4 divisors (see below), whose sum is σ = 20506472064. Its totient is φ = 20497242636.

The previous prime is 20501857333. The next prime is 20501857351. The reversal of 20501857349 is 94375810502.

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, and also an emirpimes, since its reverse is a distinct semiprime: 94375810502 = 2 ⋅47187905251.

It is a cyclic number.

It is not a de Polignac number, because 20501857349 - 2⁴ = 20501857333 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 (20501857399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2300687 + ... + 2309580.

It is an arithmetic number, because the mean of its divisors is an integer number (5126618016).

Almost surely, 2^20501857349 is an apocalyptic number.

It is an amenable number.

20501857349 is a deficient number, since it is larger than the sum of its proper divisors (4614715).

20501857349 is an equidigital number, since it uses as much as digits as its factorization.

20501857349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4614714.

The product of its (nonzero) digits is 302400, while the sum is 44.

The spelling of 20501857349 in words is "twenty billion, five hundred one million, eight hundred fifty-seven thousand, three hundred forty-nine".