1028636432557 has 8 divisors (see below), whose sum is σ = 1070999311032. Its totient is φ = 987096134400.

The previous prime is 1028636432507. The next prime is 1028636432561. The reversal of 1028636432557 is 7552346368201.

It can be written as a sum of positive squares in 4 ways, for example, as 283981344201 + 744655088356 = 532899^2 + 862934^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1028636432557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1028636432507) 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, 205642528 + ... + 205647529.

It is an arithmetic number, because the mean of its divisors is an integer number (133874913879).

Almost surely, 2^{1028636432557} is an apocalyptic number.

It is an amenable number.

1028636432557 is a deficient number, since it is larger than the sum of its proper divisors (42362878475).

1028636432557 is an equidigital number, since it uses as much as digits as its factorization.

1028636432557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411290159.

The product of its (nonzero) digits is 7257600, while the sum is 52.

The spelling of 1028636432557 in words is "one trillion, twenty-eight billion, six hundred thirty-six million, four hundred thirty-two thousand, five hundred fifty-seven".