1621404516 has 24 divisors (see below), whose sum is σ = 3804184384. Its totient is φ = 537481440.

The previous prime is 1621404511. The next prime is 1621404553. The reversal of 1621404516 is 6154041261.

It is not an unprimeable number, because it can be changed into a prime (1621404511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371080 + ... + 375423.

Almost surely, 2^1621404516 is an apocalyptic number.

It is an amenable number.

1621404516 is an abundant number, since it is smaller than the sum of its proper divisors (2182779868).

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

1621404516 is a wasteful number, since it uses less digits than its factorization.

1621404516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746691 (or 746689 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 1621404516 is about 40266.6675551876. The cubic root of 1621404516 is about 1174.7996075338.

Adding to 1621404516 its reverse (6154041261), we get a palindrome (7775445777).

The spelling of 1621404516 in words is "one billion, six hundred twenty-one million, four hundred four thousand, five hundred sixteen".