397770981 has 8 divisors (see below), whose sum is σ = 561559104. Its totient is φ = 249581760.

The previous prime is 397770977. The next prime is 397770983. The reversal of 397770981 is 189077793.

It is a happy number.

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

It is not a de Polignac number, because 397770981 - 2² = 397770977 is a prime.

It is a super-2 number, since 2×397770981² = 316443506651404722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 7799431 = 397770981 / (3 + 9 + 7 + 7 + 7 + 0 + 9 + 8 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397770983) 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, 3899665 + ... + 3899766.

It is an arithmetic number, because the mean of its divisors is an integer number (70194888).

Almost surely, 2^397770981 is an apocalyptic number.

It is an amenable number.

397770981 is a deficient number, since it is larger than the sum of its proper divisors (163788123).

397770981 is a wasteful number, since it uses less digits than its factorization.

397770981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7799451.

The product of its (nonzero) digits is 666792, while the sum is 51.

The square root of 397770981 is about 19944.1966747222. The cubic root of 397770981 is about 735.4351202097.

The spelling of 397770981 in words is "three hundred ninety-seven million, seven hundred seventy thousand, nine hundred eighty-one".