21250443402434 has 4 divisors (see below), whose sum is σ = 31875665103654. Its totient is φ = 10625221701216.

The previous prime is 21250443402431. The next prime is 21250443402451. The reversal of 21250443402434 is 43420434405212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21237765318025 + 12678084409 = 4608445^2 + 112597^2 .

It is a super-3 number, since 3×21250443402434³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21250443402431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5312610850607 + ... + 5312610850610.

Almost surely, 2^{21250443402434} is an apocalyptic number.

21250443402434 is a deficient number, since it is larger than the sum of its proper divisors (10625221701220).

21250443402434 is a wasteful number, since it uses less digits than its factorization.

21250443402434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10625221701219.

The product of its (nonzero) digits is 368640, while the sum is 38.

Adding to 21250443402434 its reverse (43420434405212), we get a palindrome (64670877807646).

The spelling of 21250443402434 in words is "twenty-one trillion, two hundred fifty billion, four hundred forty-three million, four hundred two thousand, four hundred thirty-four".