1621389740 has 24 divisors (see below), whose sum is σ = 3417876000. Its totient is φ = 646087808.

The previous prime is 1621389709. The next prime is 1621389743. The reversal of 1621389740 is 479831261.

It is not an unprimeable number, because it can be changed into a prime (1621389743) 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, 148865 + ... + 159384.

It is an arithmetic number, because the mean of its divisors is an integer number (142411500).

Almost surely, 2^1621389740 is an apocalyptic number.

1621389740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621389740 is an abundant number, since it is smaller than the sum of its proper divisors (1796486260).

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

1621389740 is a wasteful number, since it uses less digits than its factorization.

1621389740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308521 (or 308519 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 1621389740 is about 40266.4840779525. The cubic root of 1621389740 is about 1174.7960388394.

The spelling of 1621389740 in words is "one billion, six hundred twenty-one million, three hundred eighty-nine thousand, seven hundred forty".