21990546557 has 8 divisors (see below), whose sum is σ = 25184524800. Its totient is φ = 18809686224.

The previous prime is 21990546547. The next prime is 21990546559. The reversal of 21990546557 is 75564509912.

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

It is not a de Polignac number, because 21990546557 - 2¹² = 21990542461 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21990546499 and 21990546508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21990546559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3275882 + ... + 3282587.

It is an arithmetic number, because the mean of its divisors is an integer number (3148065600).

Almost surely, 2^21990546557 is an apocalyptic number.

It is an amenable number.

21990546557 is a deficient number, since it is larger than the sum of its proper divisors (3193978243).

21990546557 is an equidigital number, since it uses as much as digits as its factorization.

21990546557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6558955.

The product of its (nonzero) digits is 3402000, while the sum is 53.

The spelling of 21990546557 in words is "twenty-one billion, nine hundred ninety million, five hundred forty-six thousand, five hundred fifty-seven".