21073008637738 has 4 divisors (see below), whose sum is σ = 31609512956610. Its totient is φ = 10536504318868.

The previous prime is 21073008637669. The next prime is 21073008637739. The reversal of 21073008637738 is 83773680037012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13794813654769 + 7278194982969 = 3714137^2 + 2697813^2 .

It is a super-3 number, since 3×21073008637738³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21073008637739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5268252159433 + ... + 5268252159436.

Almost surely, 2^{21073008637738} is an apocalyptic number.

21073008637738 is a deficient number, since it is larger than the sum of its proper divisors (10536504318872).

21073008637738 is a wasteful number, since it uses less digits than its factorization.

21073008637738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10536504318871.

The product of its (nonzero) digits is 7112448, while the sum is 55.

The spelling of 21073008637738 in words is "twenty-one trillion, seventy-three billion, eight million, six hundred thirty-seven thousand, seven hundred thirty-eight".