21954208619 has 8 divisors (see below), whose sum is σ = 25147165440. Its totient is φ = 18775412136.

The previous prime is 21954208583. The next prime is 21954208621. The reversal of 21954208619 is 91680245912.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21954208619 - 2¹⁶ = 21954143083 is a prime.

It is a super-2 number, since 2×21954208619² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21954208669) 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, 3536759 + ... + 3542960.

It is an arithmetic number, because the mean of its divisors is an integer number (3143395680).

Almost surely, 2^21954208619 is an apocalyptic number.

21954208619 is a deficient number, since it is larger than the sum of its proper divisors (3192956821).

21954208619 is an equidigital number, since it uses as much as digits as its factorization.

21954208619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7080169.

The product of its (nonzero) digits is 311040, while the sum is 47.

The spelling of 21954208619 in words is "twenty-one billion, nine hundred fifty-four million, two hundred eight thousand, six hundred nineteen".