21042651630 has 192 divisors, whose sum is σ = 69018905088. Its totient is φ = 4036112640.

The previous prime is 21042651611. The next prime is 21042651661. The reversal of 21042651630 is 3615624012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 160159 + ... + 260261.

It is an arithmetic number, because the mean of its divisors is an integer number (359473464).

Almost surely, 2^21042651630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21042651630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34509452544).

21042651630 is an abundant number, since it is smaller than the sum of its proper divisors (47976253458).

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

21042651630 is a wasteful number, since it uses less digits than its factorization.

21042651630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100151 (or 100144 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 21042651630 in words is "twenty-one billion, forty-two million, six hundred fifty-one thousand, six hundred thirty".