21988907450 has 12 divisors (see below), whose sum is σ = 40899367950. Its totient is φ = 8795562960.

The previous prime is 21988907429. The next prime is 21988907471. The reversal of 21988907450 is 5470988912.

It is an interprime number because it is at equal distance from previous prime (21988907429) and next prime (21988907471).

It can be written as a sum of positive squares in 3 ways, for example, as 21490680409 + 498227041 = 146597^2 + 22321^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21988907392 and 21988907401.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 219889025 + ... + 219889124.

Almost surely, 2^21988907450 is an apocalyptic number.

21988907450 is a deficient number, since it is larger than the sum of its proper divisors (18910460500).

21988907450 is a wasteful number, since it uses less digits than its factorization.

21988907450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439778161 (or 439778156 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 53.

The spelling of 21988907450 in words is "twenty-one billion, nine hundred eighty-eight million, nine hundred seven thousand, four hundred fifty".