129920921990 has 32 divisors (see below), whose sum is σ = 241027017120. Its totient is φ = 50385106944.

The previous prime is 129920921989. The next prime is 129920922023. The reversal of 129920921990 is 99129029921.

It is a super-3 number, since 3×129920921990³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 515675 + ... + 725094.

It is an arithmetic number, because the mean of its divisors is an integer number (7532094285).

Almost surely, 2^129920921990 is an apocalyptic number.

129920921990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

129920921990 is a deficient number, since it is larger than the sum of its proper divisors (111106095130).

129920921990 is a wasteful number, since it uses less digits than its factorization.

129920921990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241096.

The product of its (nonzero) digits is 472392, while the sum is 53.

The spelling of 129920921990 in words is "one hundred twenty-nine billion, nine hundred twenty million, nine hundred twenty-one thousand, nine hundred ninety".