128620251 has 16 divisors (see below), whose sum is σ = 195700000. Its totient is φ = 83428704.

The previous prime is 128620231. The next prime is 128620259. The reversal of 128620251 is 152026821.

It is a happy number.

128620251 is a `hidden beast` number, since 12 + 8 + 620 + 25 + 1 = 666.

It is not a de Polignac number, because 128620251 - 2⁶ = 128620187 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128620259) 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 15 ways as a sum of consecutive naturals, for example, 63376 + ... + 65373.

It is an arithmetic number, because the mean of its divisors is an integer number (12231250).

Almost surely, 2^128620251 is an apocalyptic number.

128620251 is a deficient number, since it is larger than the sum of its proper divisors (67079749).

128620251 is a wasteful number, since it uses less digits than its factorization.

128620251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128795 (or 128789 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 128620251 is about 11341.0868526786. The cubic root of 128620251 is about 504.7811370656.

The spelling of 128620251 in words is "one hundred twenty-eight million, six hundred twenty thousand, two hundred fifty-one".