157281009 has 4 divisors (see below), whose sum is σ = 209708016. Its totient is φ = 104854004.

The previous prime is 157281001. The next prime is 157281017. The reversal of 157281009 is 900182751.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (157281001) and next prime (157281017).

It is a cyclic number.

It is not a de Polignac number, because 157281009 - 2³ = 157281001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (157281001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26213499 + ... + 26213504.

It is an arithmetic number, because the mean of its divisors is an integer number (52427004).

Almost surely, 2^157281009 is an apocalyptic number.

It is an amenable number.

157281009 is a deficient number, since it is larger than the sum of its proper divisors (52427007).

157281009 is an equidigital number, since it uses as much as digits as its factorization.

157281009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52427006.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 157281009 is about 12541.1725528357. The cubic root of 157281009 is about 539.7907385331.

The spelling of 157281009 in words is "one hundred fifty-seven million, two hundred eighty-one thousand, nine".