3561626621 has 4 divisors (see below), whose sum is σ = 4070430432. Its totient is φ = 3052822812.

The previous prime is 3561626603. The next prime is 3561626639. The reversal of 3561626621 is 1266261653.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1266261653 = 8807 ⋅143779.

It is an interprime number because it is at equal distance from previous prime (3561626603) and next prime (3561626639).

It is a cyclic number.

It is not a de Polignac number, because 3561626621 - 2²⁶ = 3494517757 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 (3561626641) 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, 254401895 + ... + 254401908.

It is an arithmetic number, because the mean of its divisors is an integer number (1017607608).

Almost surely, 2^3561626621 is an apocalyptic number.

It is an amenable number.

3561626621 is a deficient number, since it is larger than the sum of its proper divisors (508803811).

3561626621 is an equidigital number, since it uses as much as digits as its factorization.

3561626621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508803810.

The product of its digits is 77760, while the sum is 38.

The square root of 3561626621 is about 59679.3651189421. The cubic root of 3561626621 is about 1527.1538671576.

The spelling of 3561626621 in words is "three billion, five hundred sixty-one million, six hundred twenty-six thousand, six hundred twenty-one".