397213219661 has 2 divisors, whose sum is σ = 397213219662. Its totient is φ = 397213219660.

The previous prime is 397213219657. The next prime is 397213219717. The reversal of 397213219661 is 166912312793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221023157161 + 176190062500 = 470131^2 + 419750^2 .

It is a cyclic number.

It is not a de Polignac number, because 397213219661 - 2² = 397213219657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397213219621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198606609830 + 198606609831.

It is an arithmetic number, because the mean of its divisors is an integer number (198606609831).

Almost surely, 2^397213219661 is an apocalyptic number.

It is an amenable number.

397213219661 is a deficient number, since it is larger than the sum of its proper divisors (1).

397213219661 is an equidigital number, since it uses as much as digits as its factorization.

397213219661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 50.

The spelling of 397213219661 in words is "three hundred ninety-seven billion, two hundred thirteen million, two hundred nineteen thousand, six hundred sixty-one".