21154343502 has 16 divisors (see below), whose sum is σ = 42311711232. Its totient is φ = 7050943800.

The previous prime is 21154343491. The next prime is 21154343513. The reversal of 21154343502 is 20534345112.

It is an interprime number because it is at equal distance from previous prime (21154343491) and next prime (21154343513).

It is a self number, because there is not a number n which added to its sum of digits gives 21154343502.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 29374 + ... + 207777.

It is an arithmetic number, because the mean of its divisors is an integer number (2644481952).

Almost surely, 2^21154343502 is an apocalyptic number.

21154343502 is an abundant number, since it is smaller than the sum of its proper divisors (21157367730).

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

21154343502 is a wasteful number, since it uses less digits than its factorization.

21154343502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252023.

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 21154343502 its reverse (20534345112), we get a palindrome (41688688614).

The spelling of 21154343502 in words is "twenty-one billion, one hundred fifty-four million, three hundred forty-three thousand, five hundred two".