129749550 has 144 divisors (see below), whose sum is σ = 379975680. Its totient is φ = 29211840.

The previous prime is 129749531. The next prime is 129749551. The reversal of 129749550 is 55947921.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129749551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 933381 + ... + 933519.

It is an arithmetic number, because the mean of its divisors is an integer number (2638720).

Almost surely, 2^129749550 is an apocalyptic number.

129749550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 129749550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189987840).

129749550 is an abundant number, since it is smaller than the sum of its proper divisors (250226130).

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

129749550 is a wasteful number, since it uses less digits than its factorization.

129749550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 42.

The square root of 129749550 is about 11390.7659970697. The cubic root of 129749550 is about 506.2541776823.

The spelling of 129749550 in words is "one hundred twenty-nine million, seven hundred forty-nine thousand, five hundred fifty".