42157397 has 2 divisors, whose sum is σ = 42157398. Its totient is φ = 42157396.

The previous prime is 42157391. The next prime is 42157421. The reversal of 42157397 is 79375124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39828721 + 2328676 = 6311^2 + 1526^2 .

It is a cyclic number.

It is not a de Polignac number, because 42157397 - 2¹⁸ = 41895253 is a prime.

It is a super-2 number, since 2×42157397² = 3554492243631218, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42157397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42157391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21078698 + 21078699.

It is an arithmetic number, because the mean of its divisors is an integer number (21078699).

Almost surely, 2^42157397 is an apocalyptic number.

It is an amenable number.

42157397 is a deficient number, since it is larger than the sum of its proper divisors (1).

42157397 is an equidigital number, since it uses as much as digits as its factorization.

42157397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52920, while the sum is 38.

The square root of 42157397 is about 6492.8727848311. The cubic root of 42157397 is about 348.0363423753.

The spelling of 42157397 in words is "forty-two million, one hundred fifty-seven thousand, three hundred ninety-seven".