21249306741 has 16 divisors (see below), whose sum is σ = 30514796480. Its totient is φ = 13075223040.

The previous prime is 21249306739. The next prime is 21249306803. The reversal of 21249306741 is 14760394212.

It is not a de Polignac number, because 21249306741 - 2¹ = 21249306739 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21249306741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21249306721) 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, 523350 + ... + 562488.

It is an arithmetic number, because the mean of its divisors is an integer number (1907174780).

Almost surely, 2^21249306741 is an apocalyptic number.

It is an amenable number.

21249306741 is a deficient number, since it is larger than the sum of its proper divisors (9265489739).

21249306741 is a wasteful number, since it uses less digits than its factorization.

21249306741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53076.

The product of its (nonzero) digits is 72576, while the sum is 39.

The spelling of 21249306741 in words is "twenty-one billion, two hundred forty-nine million, three hundred six thousand, seven hundred forty-one".