397749661 has 2 divisors, whose sum is σ = 397749662. Its totient is φ = 397749660.

The previous prime is 397749659. The next prime is 397749679. The reversal of 397749661 is 166947793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 253605625 + 144144036 = 15925^2 + 12006^2 .

It is a cyclic number.

It is not a de Polignac number, because 397749661 - 2¹ = 397749659 is a prime.

It is a super-2 number, since 2×397749661² = 316409585651229842, which contains 22 as substring.

Together with 397749659, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 397749599 and 397749608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397749601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198874830 + 198874831.

It is an arithmetic number, because the mean of its divisors is an integer number (198874831).

Almost surely, 2^397749661 is an apocalyptic number.

It is an amenable number.

397749661 is a deficient number, since it is larger than the sum of its proper divisors (1).

397749661 is an equidigital number, since it uses as much as digits as its factorization.

397749661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1714608, while the sum is 52.

The square root of 397749661 is about 19943.6621762404. The cubic root of 397749661 is about 735.4219805241.

The spelling of 397749661 in words is "three hundred ninety-seven million, seven hundred forty-nine thousand, six hundred sixty-one".