20407587851 has 4 divisors (see below), whose sum is σ = 23322957552. Its totient is φ = 17492218152.

The previous prime is 20407587841. The next prime is 20407587869. The reversal of 20407587851 is 15878570402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15878570402 = 2 ⋅7939285201.

It is a cyclic number.

It is not a de Polignac number, because 20407587851 - 2¹⁰ = 20407586827 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20407587796 and 20407587805.

It is not an unprimeable number, because it can be changed into a prime (20407587841) 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, 1457684840 + ... + 1457684853.

It is an arithmetic number, because the mean of its divisors is an integer number (5830739388).

Almost surely, 2^20407587851 is an apocalyptic number.

20407587851 is a deficient number, since it is larger than the sum of its proper divisors (2915369701).

20407587851 is an equidigital number, since it uses as much as digits as its factorization.

20407587851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2915369700.

The product of its (nonzero) digits is 627200, while the sum is 47.

The spelling of 20407587851 in words is "twenty billion, four hundred seven million, five hundred eighty-seven thousand, eight hundred fifty-one".