21220749534 has 32 divisors (see below), whose sum is σ = 43151014656. Its totient is φ = 6956296640.

The previous prime is 21220749499. The next prime is 21220749541. The reversal of 21220749534 is 43594702212.

It is a super-2 number, since 2×21220749534² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21220749492 and 21220749501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32682 + ... + 208589.

It is an arithmetic number, because the mean of its divisors is an integer number (1348469208).

Almost surely, 2^21220749534 is an apocalyptic number.

21220749534 is an abundant number, since it is smaller than the sum of its proper divisors (21930265122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21220749534 is a wasteful number, since it uses less digits than its factorization.

21220749534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241520.

The product of its (nonzero) digits is 120960, while the sum is 39.

The spelling of 21220749534 in words is "twenty-one billion, two hundred twenty million, seven hundred forty-nine thousand, five hundred thirty-four".