157491409 has 2 divisors, whose sum is σ = 157491410. Its totient is φ = 157491408.

The previous prime is 157491403. The next prime is 157491427. The reversal of 157491409 is 904194751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156325009 + 1166400 = 12503^2 + 1080^2 .

It is a cyclic number.

It is not a de Polignac number, because 157491409 - 2³ = 157491401 is a prime.

It is a super-3 number, since 3×157491409³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (157491401) 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, 78745704 + 78745705.

It is an arithmetic number, because the mean of its divisors is an integer number (78745705).

Almost surely, 2^157491409 is an apocalyptic number.

It is an amenable number.

157491409 is a deficient number, since it is larger than the sum of its proper divisors (1).

157491409 is an equidigital number, since it uses as much as digits as its factorization.

157491409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 157491409 is about 12549.5581197108. The cubic root of 157491409 is about 540.0313299152.

The spelling of 157491409 in words is "one hundred fifty-seven million, four hundred ninety-one thousand, four hundred nine".