1621505085 has 16 divisors (see below), whose sum is σ = 2595701376. Its totient is φ = 864371648.

The previous prime is 1621505047. The next prime is 1621505089. The reversal of 1621505085 is 5805051261.

It is a cyclic number.

It is not a de Polignac number, because 1621505085 - 2⁶ = 1621505021 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621505089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5407 + ... + 57203.

It is an arithmetic number, because the mean of its divisors is an integer number (162231336).

Almost surely, 2^1621505085 is an apocalyptic number.

1621505085 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621505085 is a deficient number, since it is larger than the sum of its proper divisors (974196291).

1621505085 is a wasteful number, since it uses less digits than its factorization.

1621505085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53892.

The product of its (nonzero) digits is 12000, while the sum is 33.

The square root of 1621505085 is about 40267.9163230481. The cubic root of 1621505085 is about 1174.8238963480.

The spelling of 1621505085 in words is "one billion, six hundred twenty-one million, five hundred five thousand, eighty-five".