990557243 has 8 divisors (see below), whose sum is σ = 1069924128. Its totient is φ = 911643264.

The previous prime is 990557233. The next prime is 990557257. The reversal of 990557243 is 342755099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990557243 is a prime.

It is a super-2 number, since 2×990557243² = 1962407303319522098, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 990557194 and 990557203.

It is not an unprimeable number, because it can be changed into a prime (990557233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108671 + ... + 117432.

It is an arithmetic number, because the mean of its divisors is an integer number (133740516).

Almost surely, 2^990557243 is an apocalyptic number.

990557243 is a deficient number, since it is larger than the sum of its proper divisors (79366885).

990557243 is a wasteful number, since it uses less digits than its factorization.

990557243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226453.

The product of its (nonzero) digits is 340200, while the sum is 44.

The square root of 990557243 is about 31473.1193719339. The cubic root of 990557243 is about 996.8424547349.

The spelling of 990557243 in words is "nine hundred ninety million, five hundred fifty-seven thousand, two hundred forty-three".