7745428781 has 8 divisors (see below), whose sum is σ = 7958430744. Its totient is φ = 7532619840.

The previous prime is 7745428763. The next prime is 7745428787. The reversal of 7745428781 is 1878245477.

It can be written as a sum of positive squares in 4 ways, for example, as 6136215556 + 1609213225 = 78334^2 + 40115^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-7745428781 is a prime.

It is a super-2 number, since 2×7745428781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7745428787) 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, 35051 + ... + 129303.

It is an arithmetic number, because the mean of its divisors is an integer number (994803843).

Almost surely, 2^7745428781 is an apocalyptic number.

It is an amenable number.

7745428781 is a deficient number, since it is larger than the sum of its proper divisors (213001963).

7745428781 is a wasteful number, since it uses less digits than its factorization.

7745428781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96511.

The product of its digits is 3512320, while the sum is 53.

The square root of 7745428781 is about 88008.1176994486. The cubic root of 7745428781 is about 1978.5566446754.

The spelling of 7745428781 in words is "seven billion, seven hundred forty-five million, four hundred twenty-eight thousand, seven hundred eighty-one".