157279993 has 4 divisors (see below), whose sum is σ = 169378468. Its totient is φ = 145181520.

The previous prime is 157279987. The next prime is 157280047. The reversal of 157279993 is 399972751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399972751 = 1297 ⋅308383.

It can be written as a sum of positive squares in 2 ways, for example, as 6285049 + 150994944 = 2507^2 + 12288^2 .

It is a cyclic number.

It is not a de Polignac number, because 157279993 - 2¹³ = 157271801 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 157279993.

It is not an unprimeable number, because it can be changed into a prime (157279943) 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, 6049218 + ... + 6049243.

It is an arithmetic number, because the mean of its divisors is an integer number (42344617).

Almost surely, 2^157279993 is an apocalyptic number.

157279993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

157279993 is a deficient number, since it is larger than the sum of its proper divisors (12098475).

157279993 is a wasteful number, since it uses less digits than its factorization.

157279993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12098474.

The product of its digits is 1071630, while the sum is 52.

The square root of 157279993 is about 12541.1320461910. The cubic root of 157279993 is about 539.7895762216.

The spelling of 157279993 in words is "one hundred fifty-seven million, two hundred seventy-nine thousand, nine hundred ninety-three".