21345164511 has 16 divisors (see below), whose sum is σ = 31071772800. Its totient is φ = 12926354720.

The previous prime is 21345164443. The next prime is 21345164549. The reversal of 21345164511 is 11546154312.

It is a cyclic number.

It is not a de Polignac number, because 21345164511 - 2⁹ = 21345163999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345164311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209736 + ... + 294413.

It is an arithmetic number, because the mean of its divisors is an integer number (1941985800).

Almost surely, 2^21345164511 is an apocalyptic number.

21345164511 is a deficient number, since it is larger than the sum of its proper divisors (9726608289).

21345164511 is a wasteful number, since it uses less digits than its factorization.

21345164511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505446.

The product of its digits is 14400, while the sum is 33.

The spelling of 21345164511 in words is "twenty-one billion, three hundred forty-five million, one hundred sixty-four thousand, five hundred eleven".