1621138734 has 24 divisors (see below), whose sum is σ = 3719083680. Its totient is φ = 508592448.

The previous prime is 1621138723. The next prime is 1621138747. The reversal of 1621138734 is 4378311261.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 2648614 + ... + 2649225.

It is an arithmetic number, because the mean of its divisors is an integer number (154961820).

Almost surely, 2^1621138734 is an apocalyptic number.

1621138734 is an abundant number, since it is smaller than the sum of its proper divisors (2097944946).

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

1621138734 is a wasteful number, since it uses less digits than its factorization.

1621138734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5297864 (or 5297861 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 1621138734 is about 40263.3671468247. The cubic root of 1621138734 is about 1174.7354126442.

Adding to 1621138734 its reverse (4378311261), we get a palindrome (5999449995).

It can be divided in two parts, 16211 and 38734, that added together give a palindrome (54945).

The spelling of 1621138734 in words is "one billion, six hundred twenty-one million, one hundred thirty-eight thousand, seven hundred thirty-four".