998156797 has 4 divisors (see below), whose sum is σ = 1088898336. Its totient is φ = 907415260.

The previous prime is 998156777. The next prime is 998156801. The reversal of 998156797 is 797651899.

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 a cyclic number.

It is not a de Polignac number, because 998156797 - 2¹¹ = 998154749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998156777) 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, 45370753 + ... + 45370774.

It is an arithmetic number, because the mean of its divisors is an integer number (272224584).

Almost surely, 2^998156797 is an apocalyptic number.

998156797 is the 16888-th centered heptagonal number.

It is an amenable number.

998156797 is a deficient number, since it is larger than the sum of its proper divisors (90741539).

998156797 is a wasteful number, since it uses less digits than its factorization.

998156797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90741538.

The product of its digits is 8573040, while the sum is 61.

The square root of 998156797 is about 31593.6195615507. The cubic root of 998156797 is about 999.3852211244.

The spelling of 998156797 in words is "nine hundred ninety-eight million, one hundred fifty-six thousand, seven hundred ninety-seven".