1221996623 has 2 divisors, whose sum is σ = 1221996624. Its totient is φ = 1221996622.

The previous prime is 1221996617. The next prime is 1221996637. The reversal of 1221996623 is 3266991221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221996623 - 2⁸ = 1221996367 is a prime.

It is a super-3 number, since 3×1221996623³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221996653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610998311 + 610998312.

It is an arithmetic number, because the mean of its divisors is an integer number (610998312).

Almost surely, 2^1221996623 is an apocalyptic number.

1221996623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221996623 is an equidigital number, since it uses as much as digits as its factorization.

1221996623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 41.

The square root of 1221996623 is about 34957.0682838249. The cubic root of 1221996623 is about 1069.1123225644.

The spelling of 1221996623 in words is "one billion, two hundred twenty-one million, nine hundred ninety-six thousand, six hundred twenty-three".