21506137333706 has 4 divisors (see below), whose sum is σ = 32259206000562. Its totient is φ = 10753068666852.

The previous prime is 21506137333607. The next prime is 21506137333717. The reversal of 21506137333706 is 60733373160512.

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., 21185261535025 + 320875798681 = 4602745^2 + 566459^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5376534333425 + ... + 5376534333428.

Almost surely, 2^{21506137333706} is an apocalyptic number.

21506137333706 is a deficient number, since it is larger than the sum of its proper divisors (10753068666856).

21506137333706 is a wasteful number, since it uses less digits than its factorization.

21506137333706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10753068666855.

The product of its (nonzero) digits is 1428840, while the sum is 47.

The spelling of 21506137333706 in words is "twenty-one trillion, five hundred six billion, one hundred thirty-seven million, three hundred thirty-three thousand, seven hundred six".