19212005 has 4 divisors (see below), whose sum is σ = 23054412. Its totient is φ = 15369600.

The previous prime is 19212001. The next prime is 19212019. The reversal of 19212005 is 50021291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50021291 = 761 ⋅65731.

It can be written as a sum of positive squares in 2 ways, for example, as 12061729 + 7150276 = 3473^2 + 2674^2 .

It is not a de Polignac number, because 19212005 - 2² = 19212001 is a prime.

It is a super-2 number, since 2×19212005² = 738202272240050, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19212001) 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, 1921196 + ... + 1921205.

It is an arithmetic number, because the mean of its divisors is an integer number (5763603).

Almost surely, 2^19212005 is an apocalyptic number.

It is an amenable number.

19212005 is a deficient number, since it is larger than the sum of its proper divisors (3842407).

19212005 is an equidigital number, since it uses as much as digits as its factorization.

19212005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3842406.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 19212005 is about 4383.1501229139. The cubic root of 19212005 is about 267.8289777285.

Adding to 19212005 its reverse (50021291), we get a palindrome (69233296).

The spelling of 19212005 in words is "nineteen million, two hundred twelve thousand, five".