1999420351 has 4 divisors (see below), whose sum is σ = 2001929832. Its totient is φ = 1996910872.

The previous prime is 1999420349. The next prime is 1999420387. The reversal of 1999420351 is 1530249991.

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

It is a cyclic number.

It is not a de Polignac number, because 1999420351 - 2¹ = 1999420349 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1999420298 and 1999420307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999420151) 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, 1253545 + ... + 1255138.

It is an arithmetic number, because the mean of its divisors is an integer number (500482458).

Almost surely, 2^1999420351 is an apocalyptic number.

1999420351 is a deficient number, since it is larger than the sum of its proper divisors (2509481).

1999420351 is an equidigital number, since it uses as much as digits as its factorization.

1999420351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2509480.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 1999420351 is about 44714.8784075278. The cubic root of 1999420351 is about 1259.7993194712.

The spelling of 1999420351 in words is "one billion, nine hundred ninety-nine million, four hundred twenty thousand, three hundred fifty-one".