21154200520550 has 48 divisors (see below), whose sum is σ = 39385777326000. Its totient is φ = 8453302387200.

The previous prime is 21154200520499. The next prime is 21154200520559. The reversal of 21154200520550 is 5502500245112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154200520559) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 942647330 + ... + 942669770.

It is an arithmetic number, because the mean of its divisors is an integer number (820537027625).

Almost surely, 2^{21154200520550} is an apocalyptic number.

21154200520550 is a deficient number, since it is larger than the sum of its proper divisors (18231576805450).

21154200520550 is a wasteful number, since it uses less digits than its factorization.

21154200520550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40281 (or 40276 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 32.

Adding to 21154200520550 its reverse (5502500245112), we get a palindrome (26656700765662).

The spelling of 21154200520550 in words is "twenty-one trillion, one hundred fifty-four billion, two hundred million, five hundred twenty thousand, five hundred fifty".