1021631616 has 160 divisors (see below), whose sum is σ = 3061309680. Its totient is φ = 338204160.

The previous prime is 1021631591. The next prime is 1021631617. The reversal of 1021631616 is 6161361201.

1021631616 is a `hidden beast` number, since 1 + 0 + 2 + 16 + 31 + 616 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 1021631616.

It is not an unprimeable number, because it can be changed into a prime (1021631617) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2187415 + ... + 2187881.

Almost surely, 2^1021631616 is an apocalyptic number.

1021631616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1021631616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1530654840).

1021631616 is an abundant number, since it is smaller than the sum of its proper divisors (2039678064).

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

1021631616 is an equidigital number, since it uses as much as digits as its factorization.

1021631616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704 (or 683 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1021631616 is about 31962.9725776562. The cubic root of 1021631616 is about 1007.1591627445.

Adding to 1021631616 its reverse (6161361201), we get a palindrome (7182992817).

The spelling of 1021631616 in words is "one billion, twenty-one million, six hundred thirty-one thousand, six hundred sixteen".