511999421 has 4 divisors (see below), whose sum is σ = 542117052. Its totient is φ = 481881792.

The previous prime is 511999417. The next prime is 511999457. The reversal of 511999421 is 124999115.

It is a happy number.

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 230128900 + 281870521 = 15170^2 + 16789^2 .

It is a cyclic number.

It is not a de Polignac number, because 511999421 - 2² = 511999417 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 (511990421) 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, 15058790 + ... + 15058823.

It is an arithmetic number, because the mean of its divisors is an integer number (135529263).

Almost surely, 2^511999421 is an apocalyptic number.

It is an amenable number.

511999421 is a deficient number, since it is larger than the sum of its proper divisors (30117631).

511999421 is a wasteful number, since it uses less digits than its factorization.

511999421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30117630.

The product of its digits is 29160, while the sum is 41.

The square root of 511999421 is about 22627.4042037526. The cubic root of 511999421 is about 799.9996984374. Note that the first 3 decimals are identical.

The spelling of 511999421 in words is "five hundred eleven million, nine hundred ninety-nine thousand, four hundred twenty-one".