155221541 has 4 divisors (see below), whose sum is σ = 155275500. Its totient is φ = 155167584.

The previous prime is 155221523. The next prime is 155221553. The reversal of 155221541 is 145122551.

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 28569025 + 126652516 = 5345^2 + 11254^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155221541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 155221541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155221511) 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, 22406 + ... + 28503.

It is an arithmetic number, because the mean of its divisors is an integer number (38818875).

Almost surely, 2^155221541 is an apocalyptic number.

It is an amenable number.

155221541 is a deficient number, since it is larger than the sum of its proper divisors (53959).

155221541 is an equidigital number, since it uses as much as digits as its factorization.

155221541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53958.

The product of its digits is 2000, while the sum is 26.

The square root of 155221541 is about 12458.7937217052. The cubic root of 155221541 is about 537.4243380789.

The spelling of 155221541 in words is "one hundred fifty-five million, two hundred twenty-one thousand, five hundred forty-one".