155241021 has 16 divisors (see below), whose sum is σ = 223138944. Its totient is φ = 95434944.

The previous prime is 155241019. The next prime is 155241067. The reversal of 155241021 is 120142551.

It is not a de Polignac number, because 155241021 - 2¹ = 155241019 is a prime.

It is a super-2 number, since 2×155241021² = 48199549202244882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155241071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61435 + ... + 63911.

It is an arithmetic number, because the mean of its divisors is an integer number (13946184).

Almost surely, 2^155241021 is an apocalyptic number.

It is an amenable number.

155241021 is a deficient number, since it is larger than the sum of its proper divisors (67897923).

155241021 is a wasteful number, since it uses less digits than its factorization.

155241021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4100.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 155241021 is about 12459.5754743089. The cubic root of 155241021 is about 537.4468190398.

Adding to 155241021 its reverse (120142551), we get a palindrome (275383572).

The spelling of 155241021 in words is "one hundred fifty-five million, two hundred forty-one thousand, twenty-one".