990345421 has 8 divisors (see below), whose sum is σ = 1129262904. Its totient is φ = 860390400.

The previous prime is 990345409. The next prime is 990345449. The reversal of 990345421 is 124543099.

It can be written as a sum of positive squares in 4 ways, for example, as 345439396 + 644906025 = 18586^2 + 25395^2 .

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

It is not a de Polignac number, because 990345421 - 2²³ = 981956813 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 (990345491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2240380 + ... + 2240821.

It is an arithmetic number, because the mean of its divisors is an integer number (141157863).

Almost surely, 2^990345421 is an apocalyptic number.

It is an amenable number.

990345421 is a deficient number, since it is larger than the sum of its proper divisors (138917483).

990345421 is a wasteful number, since it uses less digits than its factorization.

990345421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4481231.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 990345421 is about 31469.7540664048. The cubic root of 990345421 is about 996.7713943236.

It can be divided in two parts, 9903454 and 21, that added together give a triangular number (9903475 = T₄₄₅₀).

The spelling of 990345421 in words is "nine hundred ninety million, three hundred forty-five thousand, four hundred twenty-one".