2106216451421 has 2 divisors, whose sum is σ = 2106216451422. Its totient is φ = 2106216451420.

The previous prime is 2106216451393. The next prime is 2106216451439. The reversal of 2106216451421 is 1241546126012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1453497883321 + 652718568100 = 1205611^2 + 807910^2 .

It is a cyclic number.

It is not a de Polignac number, because 2106216451421 - 2⁶ = 2106216451357 is a prime.

It is a super-2 number, since 2×2106216451421² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2106216451481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1053108225710 + 1053108225711.

It is an arithmetic number, because the mean of its divisors is an integer number (1053108225711).

Almost surely, 2^{2106216451421} is an apocalyptic number.

It is an amenable number.

2106216451421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2106216451421 is an equidigital number, since it uses as much as digits as its factorization.

2106216451421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 35.

The spelling of 2106216451421 in words is "two trillion, one hundred six billion, two hundred sixteen million, four hundred fifty-one thousand, four hundred twenty-one".