21352154449 has 2 divisors, whose sum is σ = 21352154450. Its totient is φ = 21352154448.

The previous prime is 21352154431. The next prime is 21352154497. The reversal of 21352154449 is 94445125312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16246051600 + 5106102849 = 127460^2 + 71457^2 .

It is a cyclic number.

It is not a de Polignac number, because 21352154449 - 2⁷ = 21352154321 is a prime.

It is a super-2 number, since 2×21352154449² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21355154449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676077224 + 10676077225.

It is an arithmetic number, because the mean of its divisors is an integer number (10676077225).

Almost surely, 2^21352154449 is an apocalyptic number.

It is an amenable number.

21352154449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21352154449 is an equidigital number, since it uses as much as digits as its factorization.

21352154449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The spelling of 21352154449 in words is "twenty-one billion, three hundred fifty-two million, one hundred fifty-four thousand, four hundred forty-nine".