20601615891 has 16 divisors (see below), whose sum is σ = 28121932800. Its totient is φ = 13409285568.

The previous prime is 20601615877. The next prime is 20601615907. The reversal of 20601615891 is 19851610602.

It is not a de Polignac number, because 20601615891 - 2¹³ = 20601607699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20601619891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120951 + ... + 236288.

It is an arithmetic number, because the mean of its divisors is an integer number (1757620800).

Almost surely, 2^20601615891 is an apocalyptic number.

20601615891 is a deficient number, since it is larger than the sum of its proper divisors (7520316909).

20601615891 is a wasteful number, since it uses less digits than its factorization.

20601615891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357698.

The product of its (nonzero) digits is 25920, while the sum is 39.

The spelling of 20601615891 in words is "twenty billion, six hundred one million, six hundred fifteen thousand, eight hundred ninety-one".