123421390691 has 2 divisors, whose sum is σ = 123421390692. Its totient is φ = 123421390690.

The previous prime is 123421390601. The next prime is 123421390723. The reversal of 123421390691 is 196093124321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 123421390691 - 2²² = 123417196387 is a prime.

It is a super-2 number, since 2×123421390691² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123421390601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61710695345 + 61710695346.

It is an arithmetic number, because the mean of its divisors is an integer number (61710695346).

Almost surely, 2^123421390691 is an apocalyptic number.

123421390691 is a deficient number, since it is larger than the sum of its proper divisors (1).

123421390691 is an equidigital number, since it uses as much as digits as its factorization.

123421390691 is an evil number, because the sum of its binary digits is even.

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

The spelling of 123421390691 in words is "one hundred twenty-three billion, four hundred twenty-one million, three hundred ninety thousand, six hundred ninety-one".