21206154419 has 2 divisors, whose sum is σ = 21206154420. Its totient is φ = 21206154418.

The previous prime is 21206154377. The next prime is 21206154479. The reversal of 21206154419 is 91445160212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21206154419 - 2¹² = 21206150323 is a prime.

It is a super-2 number, since 2×21206154419² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21206154479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10603077209 + 10603077210.

It is an arithmetic number, because the mean of its divisors is an integer number (10603077210).

Almost surely, 2^21206154419 is an apocalyptic number.

21206154419 is a deficient number, since it is larger than the sum of its proper divisors (1).

21206154419 is an equidigital number, since it uses as much as digits as its factorization.

21206154419 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 35.

The spelling of 21206154419 in words is "twenty-one billion, two hundred six million, one hundred fifty-four thousand, four hundred nineteen".