155077421 has 2 divisors, whose sum is σ = 155077422. Its totient is φ = 155077420.

The previous prime is 155077399. The next prime is 155077441. The reversal of 155077421 is 124770551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90516196 + 64561225 = 9514^2 + 8035^2 .

It is an emirp because it is prime and its reverse (124770551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155077421 - 2⁶ = 155077357 is a prime.

It is a super-2 number, since 2×155077421² = 48098013008022482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155077441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77538710 + 77538711.

It is an arithmetic number, because the mean of its divisors is an integer number (77538711).

Almost surely, 2^155077421 is an apocalyptic number.

It is an amenable number.

155077421 is a deficient number, since it is larger than the sum of its proper divisors (1).

155077421 is an equidigital number, since it uses as much as digits as its factorization.

155077421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9800, while the sum is 32.

The square root of 155077421 is about 12453.0085120022. The cubic root of 155077421 is about 537.2579574360.

The spelling of 155077421 in words is "one hundred fifty-five million, seventy-seven thousand, four hundred twenty-one".