155121077 has 4 divisors (see below), whose sum is σ = 155565900. Its totient is φ = 154676256.

The previous prime is 155121059. The next prime is 155121079. The reversal of 155121077 is 770121551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 50140561 + 104980516 = 7081^2 + 10246^2 .

It is a cyclic number.

It is not a de Polignac number, because 155121077 - 2¹⁶ = 155055541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155121079) 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, 221888 + ... + 222585.

It is an arithmetic number, because the mean of its divisors is an integer number (38891475).

Almost surely, 2^155121077 is an apocalyptic number.

It is an amenable number.

155121077 is a deficient number, since it is larger than the sum of its proper divisors (444823).

155121077 is an equidigital number, since it uses as much as digits as its factorization.

155121077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444822.

The product of its (nonzero) digits is 2450, while the sum is 29.

The square root of 155121077 is about 12454.7612181045. The cubic root of 155121077 is about 537.3083673811.

The spelling of 155121077 in words is "one hundred fifty-five million, one hundred twenty-one thousand, seventy-seven".