20581640379 has 8 divisors (see below), whose sum is σ = 30491319120. Its totient is φ = 13721093568.

The previous prime is 20581640377. The next prime is 20581640383. The reversal of 20581640379 is 97304618502.

20581640379 is a `hidden beast` number, since 2 + 0 + 581 + 64 + 0 + 3 + 7 + 9 = 666.

It is not a de Polignac number, because 20581640379 - 2¹ = 20581640377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20581640377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 381141462 + ... + 381141515.

It is an arithmetic number, because the mean of its divisors is an integer number (3811414890).

It is a 1-persistent number, because it is pandigital, but 2⋅20581640379 = 41163280758 is not.

Almost surely, 2^20581640379 is an apocalyptic number.

20581640379 is a deficient number, since it is larger than the sum of its proper divisors (9909678741).

20581640379 is an equidigital number, since it uses as much as digits as its factorization.

20581640379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762282986 (or 762282980 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 20581640379 in words is "twenty billion, five hundred eighty-one million, six hundred forty thousand, three hundred seventy-nine".