21219748901 has 8 divisors (see below), whose sum is σ = 22853171544. Its totient is φ = 19586488320.

The previous prime is 21219748897. The next prime is 21219748903. The reversal of 21219748901 is 10984791212.

It is a happy number.

It is a Cunningham number, because it is equal to 145670²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 21219748900 = 1^2 + 145670^2 .

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 21219748901 - 2² = 21219748897 is a prime.

It is a super-3 number, since 3×21219748901³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21219748903) 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, 466565 + ... + 510021.

It is an arithmetic number, because the mean of its divisors is an integer number (2856646443).

Almost surely, 2^21219748901 is an apocalyptic number.

It is an amenable number.

21219748901 is a deficient number, since it is larger than the sum of its proper divisors (1633422643).

21219748901 is a wasteful number, since it uses less digits than its factorization.

21219748901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81031.

The product of its (nonzero) digits is 72576, while the sum is 44.

The spelling of 21219748901 in words is "twenty-one billion, two hundred nineteen million, seven hundred forty-eight thousand, nine hundred one".