155698111421 has 2 divisors, whose sum is σ = 155698111422. Its totient is φ = 155698111420.

The previous prime is 155698111367. The next prime is 155698111423. The reversal of 155698111421 is 124111896551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155698111396 + 25 = 394586^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 155698111421 - 2¹⁴ = 155698095037 is a prime.

It is a super-2 number, since 2×155698111421² (a number of 23 digits) contains 22 as substring.

Together with 155698111423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155698111423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77849055710 + 77849055711.

It is an arithmetic number, because the mean of its divisors is an integer number (77849055711).

Almost surely, 2^155698111421 is an apocalyptic number.

It is an amenable number.

155698111421 is a deficient number, since it is larger than the sum of its proper divisors (1).

155698111421 is an equidigital number, since it uses as much as digits as its factorization.

155698111421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 44.

The spelling of 155698111421 in words is "one hundred fifty-five billion, six hundred ninety-eight million, one hundred eleven thousand, four hundred twenty-one".