21211787342551 has 8 divisors (see below), whose sum is σ = 22843517611824. Its totient is φ = 19580064833280.

The previous prime is 21211787342519. The next prime is 21211787342567. The reversal of 21211787342551 is 15524378711212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21211787342551 - 2⁵ = 21211787342519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211787342495 and 21211787342504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211787342051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4538535 + ... + 7938631.

It is an arithmetic number, because the mean of its divisors is an integer number (2855439701478).

Almost surely, 2^{21211787342551} is an apocalyptic number.

21211787342551 is a deficient number, since it is larger than the sum of its proper divisors (1631730269273).

21211787342551 is a wasteful number, since it uses less digits than its factorization.

21211787342551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3880001.

The product of its digits is 940800, while the sum is 49.

The spelling of 21211787342551 in words is "twenty-one trillion, two hundred eleven billion, seven hundred eighty-seven million, three hundred forty-two thousand, five hundred fifty-one".