997920386 has 8 divisors (see below), whose sum is σ = 1497446544. Its totient is φ = 498771540.

The previous prime is 997920331. The next prime is 997920409. The reversal of 997920386 is 683029799.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87620 + ... + 98351.

It is an arithmetic number, because the mean of its divisors is an integer number (187180818).

Almost surely, 2^997920386 is an apocalyptic number.

997920386 is the 16886-th centered heptagonal number.

997920386 is a deficient number, since it is larger than the sum of its proper divisors (499526158).

997920386 is a wasteful number, since it uses less digits than its factorization.

997920386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188656.

The product of its (nonzero) digits is 1469664, while the sum is 53.

The square root of 997920386 is about 31589.8779041642. The cubic root of 997920386 is about 999.3063142447.

The spelling of 997920386 in words is "nine hundred ninety-seven million, nine hundred twenty thousand, three hundred eighty-six".