21121545434 has 32 divisors (see below), whose sum is σ = 36592032960. Its totient is φ = 9042796800.

The previous prime is 21121545409. The next prime is 21121545439. The reversal of 21121545434 is 43454512112.

It is a super-2 number, since 2×21121545434² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121545434.

It is not an unprimeable number, because it can be changed into a prime (21121545439) 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 in 15 ways as a sum of consecutive naturals, for example, 73727 + ... + 218354.

It is an arithmetic number, because the mean of its divisors is an integer number (1143501030).

Almost surely, 2^21121545434 is an apocalyptic number.

21121545434 is a deficient number, since it is larger than the sum of its proper divisors (15470487526).

21121545434 is a wasteful number, since it uses less digits than its factorization.

21121545434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292286.

The product of its digits is 19200, while the sum is 32.

The spelling of 21121545434 in words is "twenty-one billion, one hundred twenty-one million, five hundred forty-five thousand, four hundred thirty-four".