997525778 has 18 divisors (see below), whose sum is σ = 1565785767.
Its totient is φ = 476586220.
The previous prime is 997525733. The next prime is 997525819. The reversal of 997525778 is 877525799.
It can be divided in two parts, 9975 and 25778, that added together give a palindrome (35753).
It can be written as a sum of positive squares in only one way, i.e., 498762889 + 498762889 = 22333^2 + 22333^2
It is an ABA number since it can be written as A⋅BA, here for A=2, B=22333.
It is a Duffinian number.
It is a Curzon number.
It is an unprimeable number.
It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1026833 + ... + 1027803.
Almost surely, 2997525778 is an apocalyptic number.
997525778 is a deficient number, since it is larger than the sum of its proper divisors (568259989).
997525778 is an frugal number, since it uses more digits than its factorization.
997525778 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1990 (or 996 counting only the distinct ones).
The product of its digits is 11113200, while the sum is 59.
The square root of 997525778 is about 31583.6314884783.
The cubic root of 997525778 is about 999.1745781996.
The spelling of 997525778 in words is "nine hundred ninety-seven million, five hundred twenty-five thousand, seven hundred seventy-eight".