21351387654 has 48 divisors (see below), whose sum is σ = 46452800160. Its totient is φ = 7087735680.

The previous prime is 21351387649. The next prime is 21351387661. The reversal of 21351387654 is 45678315312.

It is a happy number.

21351387654 is a `hidden beast` number, since 2 + 1 + 3 + 513 + 87 + 6 + 54 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5326519 + ... + 5330525.

It is an arithmetic number, because the mean of its divisors is an integer number (967766670).

Almost surely, 2^21351387654 is an apocalyptic number.

21351387654 is an abundant number, since it is smaller than the sum of its proper divisors (25101412506).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21351387654 is a wasteful number, since it uses less digits than its factorization.

21351387654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5165 (or 5162 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 21351387654 in words is "twenty-one billion, three hundred fifty-one million, three hundred eighty-seven thousand, six hundred fifty-four".