2621664761 has 4 divisors (see below), whose sum is σ = 2706234624. Its totient is φ = 2537094900.

The previous prime is 2621664733. The next prime is 2621664781. The reversal of 2621664761 is 1674661262.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2621664761 - 2¹⁴ = 2621648377 is a prime.

It is a super-2 number, since 2×2621664761² = 13746252238138374242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2621664781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42284885 + ... + 42284946.

It is an arithmetic number, because the mean of its divisors is an integer number (676558656).

Almost surely, 2^2621664761 is an apocalyptic number.

It is an amenable number.

2621664761 is a deficient number, since it is larger than the sum of its proper divisors (84569863).

2621664761 is an equidigital number, since it uses as much as digits as its factorization.

2621664761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84569862.

The product of its digits is 145152, while the sum is 41.

The square root of 2621664761 is about 51202.1948845945. The cubic root of 2621664761 is about 1378.8776074681.

The spelling of 2621664761 in words is "two billion, six hundred twenty-one million, six hundred sixty-four thousand, seven hundred sixty-one".