21001545224252 has 48 divisors (see below), whose sum is σ = 38962239624000. Its totient is φ = 9885275389440.

The previous prime is 21001545224249. The next prime is 21001545224293. The reversal of 21001545224252 is 25242254510012.

It is a happy number.

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, 5533649 + ... + 8521992.

It is an arithmetic number, because the mean of its divisors is an integer number (811713325500).

Almost surely, 2^{21001545224252} is an apocalyptic number.

It is an amenable number.

21001545224252 is a deficient number, since it is larger than the sum of its proper divisors (17960694399748).

21001545224252 is a wasteful number, since it uses less digits than its factorization.

21001545224252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14055926 (or 14055924 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 35.

Adding to 21001545224252 its reverse (25242254510012), we get a palindrome (46243799734264).

The spelling of 21001545224252 in words is "twenty-one trillion, one billion, five hundred forty-five million, two hundred twenty-four thousand, two hundred fifty-two".