997627978 has 8 divisors (see below), whose sum is σ = 1497222720. Its totient is φ = 498553740.

The previous prime is 997627973. The next prime is 997627979. The reversal of 997627978 is 879726799.

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

It is not an unprimeable number, because it can be changed into a prime (997627973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125298 + ... + 133021.

It is an arithmetic number, because the mean of its divisors is an integer number (187152840).

Almost surely, 2^997627978 is an apocalyptic number.

997627978 is a deficient number, since it is larger than the sum of its proper divisors (499594742).

997627978 is a wasteful number, since it uses less digits than its factorization.

997627978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260252.

The product of its digits is 24004512, while the sum is 64.

The square root of 997627978 is about 31585.2493737187. The cubic root of 997627978 is about 999.2087000095.

The spelling of 997627978 in words is "nine hundred ninety-seven million, six hundred twenty-seven thousand, nine hundred seventy-eight".