20745361057 has 4 divisors (see below), whose sum is σ = 20746002736. Its totient is φ = 20744719380.

The previous prime is 20745361031. The next prime is 20745361061. The reversal of 20745361057 is 75016354702.

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 a cyclic number.

It is not a de Polignac number, because 20745361057 - 2⁷ = 20745360929 is a prime.

It is the 144033-rd Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20745361027) by changing a digit.

It is a nontrivial repunit in base 144032.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269619 + ... + 337912.

It is an arithmetic number, because the mean of its divisors is an integer number (5186500684).

Almost surely, 2^20745361057 is an apocalyptic number.

It is an amenable number.

20745361057 is a deficient number, since it is larger than the sum of its proper divisors (641679).

20745361057 is an equidigital number, since it uses as much as digits as its factorization.

20745361057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641678.

The product of its (nonzero) digits is 176400, while the sum is 40.

The spelling of 20745361057 in words is "twenty billion, seven hundred forty-five million, three hundred sixty-one thousand, fifty-seven".