21406464541 has 16 divisors (see below), whose sum is σ = 26696815488. Its totient is φ = 16675214400.

The previous prime is 21406464539. The next prime is 21406464601. The reversal of 21406464541 is 14546460412.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21406464541 - 2¹ = 21406464539 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21406464541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406464241) 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, 218511 + ... + 300931.

It is an arithmetic number, because the mean of its divisors is an integer number (1668550968).

Almost surely, 2^21406464541 is an apocalyptic number.

It is an amenable number.

21406464541 is a deficient number, since it is larger than the sum of its proper divisors (5290350947).

21406464541 is a wasteful number, since it uses less digits than its factorization.

21406464541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85812.

The product of its (nonzero) digits is 92160, while the sum is 37.

The spelling of 21406464541 in words is "twenty-one billion, four hundred six million, four hundred sixty-four thousand, five hundred forty-one".