21738717554 has 4 divisors (see below), whose sum is σ = 32608076334. Its totient is φ = 10869358776.

The previous prime is 21738717541. The next prime is 21738717563. The reversal of 21738717554 is 45571783712.

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., 17581434025 + 4157283529 = 132595^2 + 64477^2 .

It is a Curzon number.

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 as a sum of consecutive naturals, namely, 5434679387 + ... + 5434679390.

Almost surely, 2^21738717554 is an apocalyptic number.

21738717554 is a deficient number, since it is larger than the sum of its proper divisors (10869358780).

21738717554 is a wasteful number, since it uses less digits than its factorization.

21738717554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10869358779.

The product of its digits is 1646400, while the sum is 50.

The spelling of 21738717554 in words is "twenty-one billion, seven hundred thirty-eight million, seven hundred seventeen thousand, five hundred fifty-four".