1626323561 has 4 divisors (see below), whose sum is σ = 1627410000. Its totient is φ = 1625237124.

The previous prime is 1626323557. The next prime is 1626323579. The reversal of 1626323561 is 1653236261.

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: 1653236261 = 53 ⋅31193137.

It is a cyclic number.

It is not a de Polignac number, because 1626323561 - 2² = 1626323557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1626323521) 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, 540971 + ... + 543968.

It is an arithmetic number, because the mean of its divisors is an integer number (406852500).

Almost surely, 2^1626323561 is an apocalyptic number.

It is an amenable number.

1626323561 is a deficient number, since it is larger than the sum of its proper divisors (1086439).

1626323561 is a wasteful number, since it uses less digits than its factorization.

1626323561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086438.

The product of its digits is 38880, while the sum is 35.

The square root of 1626323561 is about 40327.7021537305. The cubic root of 1626323561 is about 1175.9864505608.

The spelling of 1626323561 in words is "one billion, six hundred twenty-six million, three hundred twenty-three thousand, five hundred sixty-one".