21947371625361 has 16 divisors (see below), whose sum is σ = 36016199590784. Its totient is φ = 11576635582464.

The previous prime is 21947371625359. The next prime is 21947371625371. The reversal of 21947371625361 is 16352617374912.

It is not a de Polignac number, because 21947371625361 - 2¹ = 21947371625359 is a prime.

It is a super-2 number, since 2×21947371625361² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21947371625371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40196651056 + ... + 40196651601.

It is an arithmetic number, because the mean of its divisors is an integer number (2251012474424).

Almost surely, 2^{21947371625361} is an apocalyptic number.

21947371625361 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21947371625361 is a deficient number, since it is larger than the sum of its proper divisors (14068827965423).

21947371625361 is a wasteful number, since it uses less digits than its factorization.

21947371625361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80393302680.

The product of its digits is 11430720, while the sum is 57.

The spelling of 21947371625361 in words is "twenty-one trillion, nine hundred forty-seven billion, three hundred seventy-one million, six hundred twenty-five thousand, three hundred sixty-one".