21501087448 has 8 divisors (see below), whose sum is σ = 40314538980. Its totient is φ = 10750543720.

The previous prime is 21501087437. The next prime is 21501087457. The reversal of 21501087448 is 84478010512.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21501087448² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21501087448.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1343817958 + ... + 1343817973.

Almost surely, 2^21501087448 is an apocalyptic number.

It is an amenable number.

21501087448 is a deficient number, since it is larger than the sum of its proper divisors (18813451532).

21501087448 is a wasteful number, since it uses less digits than its factorization.

21501087448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2687635937 (or 2687635933 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 40.

The spelling of 21501087448 in words is "twenty-one billion, five hundred one million, eighty-seven thousand, four hundred forty-eight".