128723734 has 4 divisors (see below), whose sum is σ = 193085604. Its totient is φ = 64361866.

The previous prime is 128723731. The next prime is 128723737. The reversal of 128723734 is 437327821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 437327821 = 7 ⋅62475403.

It is an interprime number because it is at equal distance from previous prime (128723731) and next prime (128723737).

It is a junction number, because it is equal to n+sod(n) for n = 128723693 and 128723702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128723731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32180932 + ... + 32180935.

It is an arithmetic number, because the mean of its divisors is an integer number (48271401).

Almost surely, 2^128723734 is an apocalyptic number.

128723734 is a deficient number, since it is larger than the sum of its proper divisors (64361870).

128723734 is an equidigital number, since it uses as much as digits as its factorization.

128723734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64361869.

The product of its digits is 56448, while the sum is 37.

The square root of 128723734 is about 11345.6482406251. The cubic root of 128723734 is about 504.9164767268.

The spelling of 128723734 in words is "one hundred twenty-eight million, seven hundred twenty-three thousand, seven hundred thirty-four".