129292720 has 40 divisors (see below), whose sum is σ = 316430640. Its totient is φ = 48994560.

The previous prime is 129292699. The next prime is 129292727. The reversal of 129292720 is 27292921.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (129292727) 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, 41011 + ... + 44050.

It is an arithmetic number, because the mean of its divisors is an integer number (7910766).

Almost surely, 2^129292720 is an apocalyptic number.

129292720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129292720 is an abundant number, since it is smaller than the sum of its proper divisors (187137920).

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

129292720 is a wasteful number, since it uses less digits than its factorization.

129292720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85093 (or 85087 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 129292720 is about 11370.6956691312. The cubic root of 129292720 is about 505.6593289816.

The spelling of 129292720 in words is "one hundred twenty-nine million, two hundred ninety-two thousand, seven hundred twenty".