1621064540 has 12 divisors (see below), whose sum is σ = 3404235576. Its totient is φ = 648425808.

The previous prime is 1621064539. The next prime is 1621064561. The reversal of 1621064540 is 454601261.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40526594 + ... + 40526633.

It is an arithmetic number, because the mean of its divisors is an integer number (283686298).

Almost surely, 2^1621064540 is an apocalyptic number.

1621064540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621064540 is an abundant number, since it is smaller than the sum of its proper divisors (1783171036).

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

1621064540 is a wasteful number, since it uses less digits than its factorization.

1621064540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81053236 (or 81053234 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 1621064540 is about 40262.4457776723. The cubic root of 1621064540 is about 1174.7174911575.

The spelling of 1621064540 in words is "one billion, six hundred twenty-one million, sixty-four thousand, five hundred forty".