20629738581 has 8 divisors (see below), whose sum is σ = 27514274880. Its totient is φ = 13749180672.

The previous prime is 20629738579. The next prime is 20629738601. The reversal of 20629738581 is 18583792602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20629738581 - 2¹ = 20629738579 is a prime.

It is a super-2 number, since 2×20629738581² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20629738081) 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, 982476 + ... + 1003253.

It is an arithmetic number, because the mean of its divisors is an integer number (3439284360).

Almost surely, 2^20629738581 is an apocalyptic number.

It is an amenable number.

20629738581 is a deficient number, since it is larger than the sum of its proper divisors (6884536299).

20629738581 is a wasteful number, since it uses less digits than its factorization.

20629738581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989195.

The product of its (nonzero) digits is 1451520, while the sum is 51.

The spelling of 20629738581 in words is "twenty billion, six hundred twenty-nine million, seven hundred thirty-eight thousand, five hundred eighty-one".