2621603661 has 16 divisors (see below), whose sum is σ = 3673437504. Its totient is φ = 1660950144.

The previous prime is 2621603659. The next prime is 2621603707. The reversal of 2621603661 is 1663061262.

It is not a de Polignac number, because 2621603661 - 2¹ = 2621603659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2621603561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 269856 + ... + 279401.

It is an arithmetic number, because the mean of its divisors is an integer number (229589844).

Almost surely, 2^2621603661 is an apocalyptic number.

It is an amenable number.

2621603661 is a deficient number, since it is larger than the sum of its proper divisors (1051833843).

2621603661 is a wasteful number, since it uses less digits than its factorization.

2621603661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549340.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 2621603661 is about 51201.5982270085. The cubic root of 2621603661 is about 1378.8668954354.

The spelling of 2621603661 in words is "two billion, six hundred twenty-one million, six hundred three thousand, six hundred sixty-one".