21787545720244 has 12 divisors (see below), whose sum is σ = 38201107891744. Its totient is φ = 10872943465464.

The previous prime is 21787545720181. The next prime is 21787545720263. The reversal of 21787545720244 is 44202754578712.

It is a super-2 number, since 2×21787545720244² (a number of 27 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (58) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5207346312 + ... + 5207350495.

Almost surely, 2^{21787545720244} is an apocalyptic number.

It is an amenable number.

21787545720244 is a deficient number, since it is larger than the sum of its proper divisors (16413562171500).

21787545720244 is a wasteful number, since it uses less digits than its factorization.

21787545720244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10414697334 (or 10414697332 counting only the distinct ones).

The product of its (nonzero) digits is 35123200, while the sum is 58.

The spelling of 21787545720244 in words is "twenty-one trillion, seven hundred eighty-seven billion, five hundred forty-five million, seven hundred twenty thousand, two hundred forty-four".