21657915430293 has 16 divisors (see below), whose sum is σ = 28972181697536. Its totient is φ = 14391132643440.

The previous prime is 21657915430289. The next prime is 21657915430309. The reversal of 21657915430293 is 39203451975612.

It is not a de Polignac number, because 21657915430293 - 2² = 21657915430289 is a prime.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21657915430273) 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, 30792180 + ... + 31487682.

It is an arithmetic number, because the mean of its divisors is an integer number (1810761356096).

Almost surely, 2^{21657915430293} is an apocalyptic number.

It is an amenable number.

21657915430293 is a deficient number, since it is larger than the sum of its proper divisors (7314266267243).

21657915430293 is a wasteful number, since it uses less digits than its factorization.

21657915430293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729624.

The product of its (nonzero) digits is 12247200, while the sum is 57.

The spelling of 21657915430293 in words is "twenty-one trillion, six hundred fifty-seven billion, nine hundred fifteen million, four hundred thirty thousand, two hundred ninety-three".