20390129136 has 160 divisors (see below), whose sum is σ = 63114571520. Its totient is φ = 6265403136.

The previous prime is 20390129093. The next prime is 20390129153. The reversal of 20390129136 is 63192109302.

It is a happy number.

It is a super-2 number, since 2×20390129136² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20390129136.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5091711 + ... + 5095713.

It is an arithmetic number, because the mean of its divisors is an integer number (394466072).

Almost surely, 2^20390129136 is an apocalyptic number.

20390129136 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20390129136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31557285760).

20390129136 is an abundant number, since it is smaller than the sum of its proper divisors (42724442384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20390129136 is a wasteful number, since it uses less digits than its factorization.

20390129136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4940 (or 4928 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The spelling of 20390129136 in words is "twenty billion, three hundred ninety million, one hundred twenty-nine thousand, one hundred thirty-six".