990168157357 has 4 divisors (see below), whose sum is σ = 990170188540. Its totient is φ = 990166126176.

The previous prime is 990168157267. The next prime is 990168157361. The reversal of 990168157357 is 753751861099.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 678557472516 + 311610684841 = 823746^2 + 558221^2 .

It is a 3-Lehmer number, since φ(990168157357) divides (990168157357-1)³.

It is a cyclic number.

It is not a de Polignac number, because 990168157357 - 2⁷ = 990168157229 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 990168157295 and 990168157304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990168157157) 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, 203119 + ... + 1421827.

It is an arithmetic number, because the mean of its divisors is an integer number (247542547135).

Almost surely, 2^990168157357 is an apocalyptic number.

990168157357 is the 812473-rd pentagonal number.

It is an amenable number.

990168157357 is a deficient number, since it is larger than the sum of its proper divisors (2031183).

990168157357 is a wasteful number, since it uses less digits than its factorization.

990168157357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031182.

The product of its (nonzero) digits is 14288400, while the sum is 61.

The spelling of 990168157357 in words is "nine hundred ninety billion, one hundred sixty-eight million, one hundred fifty-seven thousand, three hundred fifty-seven".