918137309 has 4 divisors (see below), whose sum is σ = 972145404. Its totient is φ = 864129216.

The previous prime is 918137293. The next prime is 918137327. The reversal of 918137309 is 903731819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 903731819 = 8053 ⋅112223.

It can be written as a sum of positive squares in 2 ways, for example, as 778968100 + 139169209 = 27910^2 + 11797^2 .

It is a cyclic number.

It is not a de Polignac number, because 918137309 - 2⁴ = 918137293 is a prime.

It is a super-2 number, since 2×918137309² = 1685952236355522962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918137009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27004022 + ... + 27004055.

It is an arithmetic number, because the mean of its divisors is an integer number (243036351).

Almost surely, 2^918137309 is an apocalyptic number.

It is an amenable number.

918137309 is a deficient number, since it is larger than the sum of its proper divisors (54008095).

918137309 is a wasteful number, since it uses less digits than its factorization.

918137309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54008094.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 918137309 is about 30300.7806665109. The cubic root of 918137309 is about 971.9319941611.

The spelling of 918137309 in words is "nine hundred eighteen million, one hundred thirty-seven thousand, three hundred nine".