1620550261 has 32 divisors (see below), whose sum is σ = 1948769280. Its totient is φ = 1330243200.

The previous prime is 1620550259. The next prime is 1620550277.

1620550261 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1620550261 - 2¹ = 1620550259 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 (1620550201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2129121 + ... + 2129881.

It is an arithmetic number, because the mean of its divisors is an integer number (60899040).

Almost surely, 2^1620550261 is an apocalyptic number.

1620550261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1620550261 is a deficient number, since it is larger than the sum of its proper divisors (328219019).

1620550261 is a wasteful number, since it uses less digits than its factorization.

1620550261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1257.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 1620550261 is about 40256.0586868610. The cubic root of 1620550261 is about 1174.5932525436.

It can be divided in two parts, 16205 and 50261, that added together give a palindrome (66466).

The spelling of 1620550261 in words is "one billion, six hundred twenty million, five hundred fifty thousand, two hundred sixty-one".