20899621729351 has 2 divisors, whose sum is σ = 20899621729352. Its totient is φ = 20899621729350.

The previous prime is 20899621729333. The next prime is 20899621729423. The reversal of 20899621729351 is 15392712699802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20899621729351 - 2⁵ = 20899621729319 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20899621721351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10449810864675 + 10449810864676.

It is an arithmetic number, because the mean of its divisors is an integer number (10449810864676).

Almost surely, 2^{20899621729351} is an apocalyptic number.

20899621729351 is a deficient number, since it is larger than the sum of its proper divisors (1).

20899621729351 is an equidigital number, since it uses as much as digits as its factorization.

20899621729351 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29393280, while the sum is 64.

The spelling of 20899621729351 in words is "twenty trillion, eight hundred ninety-nine billion, six hundred twenty-one million, seven hundred twenty-nine thousand, three hundred fifty-one".