1251620128 has 36 divisors (see below), whose sum is σ = 2708511750. Its totient is φ = 568916480.

The previous prime is 1251620107. The next prime is 1251620137. The reversal of 1251620128 is 8210261521.

It can be written as a sum of positive squares in only one way, i.e., 680792464 + 570827664 = 26092^2 + 23892^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1251620096 and 1251620105.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 157753 + ... + 165496.

Almost surely, 2^1251620128 is an apocalyptic number.

It is an amenable number.

1251620128 is an abundant number, since it is smaller than the sum of its proper divisors (1456891622).

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

1251620128 is a wasteful number, since it uses less digits than its factorization.

1251620128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323281 (or 323262 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 1251620128 is about 35378.2437099413. The cubic root of 1251620128 is about 1077.6825387563.

Adding to 1251620128 its reverse (8210261521), we get a palindrome (9461881649).

The spelling of 1251620128 in words is "one billion, two hundred fifty-one million, six hundred twenty thousand, one hundred twenty-eight".