197878613 has 2 divisors, whose sum is σ = 197878614. Its totient is φ = 197878612.

The previous prime is 197878609. The next prime is 197878621. The reversal of 197878613 is 316878791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178676689 + 19201924 = 13367^2 + 4382^2 .

It is a cyclic number.

It is not a de Polignac number, because 197878613 - 2² = 197878609 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197878313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98939306 + 98939307.

It is an arithmetic number, because the mean of its divisors is an integer number (98939307).

Almost surely, 2^197878613 is an apocalyptic number.

It is an amenable number.

197878613 is a deficient number, since it is larger than the sum of its proper divisors (1).

197878613 is an equidigital number, since it uses as much as digits as its factorization.

197878613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 50.

The square root of 197878613 is about 14066.9333189576. The cubic root of 197878613 is about 582.7285360137.

The spelling of 197878613 in words is "one hundred ninety-seven million, eight hundred seventy-eight thousand, six hundred thirteen".