1621971132 has 72 divisors (see below), whose sum is σ = 3979449936. Its totient is φ = 514128384.

The previous prime is 1621971103. The next prime is 1621971133. The reversal of 1621971132 is 2311791261.

It is a super-2 number, since 2×1621971132² = 5261580706082722848, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1621971093 and 1621971102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621971133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1249908 + ... + 1251204.

It is an arithmetic number, because the mean of its divisors is an integer number (55270138).

Almost surely, 2^1621971132 is an apocalyptic number.

1621971132 is a gapful number since it is divisible by the number (12) 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 1621971132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1989724968).

1621971132 is an abundant number, since it is smaller than the sum of its proper divisors (2357478804).

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

1621971132 is a wasteful number, since it uses less digits than its factorization.

1621971132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547 (or 1522 counting only the distinct ones).

The product of its digits is 4536, while the sum is 33.

The square root of 1621971132 is about 40273.7027351596. The cubic root of 1621971132 is about 1174.9364400808.

The spelling of 1621971132 in words is "one billion, six hundred twenty-one million, nine hundred seventy-one thousand, one hundred thirty-two".