155214021 has 16 divisors (see below), whose sum is σ = 218839040. Its totient is φ = 97582320.

The previous prime is 155214019. The next prime is 155214041. The reversal of 155214021 is 120412551.

It is not a de Polignac number, because 155214021 - 2¹ = 155214019 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 (155214041) 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, 6606 + ... + 18816.

It is an arithmetic number, because the mean of its divisors is an integer number (13677440).

Almost surely, 2^155214021 is an apocalyptic number.

It is an amenable number.

155214021 is a deficient number, since it is larger than the sum of its proper divisors (63625019).

155214021 is a wasteful number, since it uses less digits than its factorization.

155214021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12456.

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

The square root of 155214021 is about 12458.4919231824. The cubic root of 155214021 is about 537.4156590939.

Adding to 155214021 its reverse (120412551), we get a palindrome (275626572).

The spelling of 155214021 in words is "one hundred fifty-five million, two hundred fourteen thousand, twenty-one".