21651767411752 has 16 divisors (see below), whose sum is σ = 40893392832660. Its totient is φ = 10746862656384.

The previous prime is 21651767411749. The next prime is 21651767411753. The reversal of 21651767411752 is 25711476715612.

It can be written as a sum of positive squares in 2 ways, for example, as 21649794808356 + 1972603396 = 4652934^2 + 44414^2 .

It is a super-2 number, since 2×21651767411752² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21651767411693 and 21651767411702.

It is not an unprimeable number, because it can be changed into a prime (21651767411753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9877630023 + ... + 9877632214.

Almost surely, 2^{21651767411752} is an apocalyptic number.

It is an amenable number.

21651767411752 is a deficient number, since it is larger than the sum of its proper divisors (19241625420908).

21651767411752 is a wasteful number, since it uses less digits than its factorization.

21651767411752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19755262380 (or 19755262376 counting only the distinct ones).

The product of its digits is 4939200, while the sum is 55.

The spelling of 21651767411752 in words is "twenty-one trillion, six hundred fifty-one billion, seven hundred sixty-seven million, four hundred eleven thousand, seven hundred fifty-two".