397977761 has 2 divisors, whose sum is σ = 397977762. Its totient is φ = 397977760.

The previous prime is 397977719. The next prime is 397977787. The reversal of 397977761 is 167779793.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 338008225 + 59969536 = 18385^2 + 7744^2 .

It is a cyclic number.

It is not a de Polignac number, because 397977761 - 2¹⁰ = 397976737 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 397977697 and 397977706.

It is not a weakly prime, because it can be changed into another prime (397977061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198988880 + 198988881.

It is an arithmetic number, because the mean of its divisors is an integer number (198988881).

Almost surely, 2^397977761 is an apocalyptic number.

It is an amenable number.

397977761 is a deficient number, since it is larger than the sum of its proper divisors (1).

397977761 is an equidigital number, since it uses as much as digits as its factorization.

397977761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3500658, while the sum is 56.

The square root of 397977761 is about 19949.3799653022. The cubic root of 397977761 is about 735.5625360155.

The spelling of 397977761 in words is "three hundred ninety-seven million, nine hundred seventy-seven thousand, seven hundred sixty-one".