1620852591 has 8 divisors (see below), whose sum is σ = 2164923904. Its totient is φ = 1078674840.

The previous prime is 1620852581. The next prime is 1620852671. The reversal of 1620852591 is 1952580261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1620852591 - 2¹³ = 1620844399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620852511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 471391 + ... + 474816.

It is an arithmetic number, because the mean of its divisors is an integer number (270615488).

Almost surely, 2^1620852591 is an apocalyptic number.

1620852591 is a deficient number, since it is larger than the sum of its proper divisors (544071313).

1620852591 is an equidigital number, since it uses as much as digits as its factorization.

1620852591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 946781.

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 1620852591 is about 40259.8135986743. The cubic root of 1620852591 is about 1174.6662920754. Note that the first 3 decimals are identical.

The spelling of 1620852591 in words is "one billion, six hundred twenty million, eight hundred fifty-two thousand, five hundred ninety-one".