155345310221 has 4 divisors (see below), whose sum is σ = 163521379200. Its totient is φ = 147169241244.

The previous prime is 155345310199. The next prime is 155345310223. The reversal of 155345310221 is 122013543551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122013543551 = 97 ⋅1257871583.

It is a cyclic number.

It is not a de Polignac number, because 155345310221 - 2²⁶ = 155278201357 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 (155345310223) 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, 4088034461 + ... + 4088034498.

It is an arithmetic number, because the mean of its divisors is an integer number (40880344800).

Almost surely, 2^155345310221 is an apocalyptic number.

It is an amenable number.

155345310221 is a deficient number, since it is larger than the sum of its proper divisors (8176068979).

155345310221 is an equidigital number, since it uses as much as digits as its factorization.

155345310221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8176068978.

The product of its (nonzero) digits is 18000, while the sum is 32.

Adding to 155345310221 its reverse (122013543551), we get a palindrome (277358853772).

The spelling of 155345310221 in words is "one hundred fifty-five billion, three hundred forty-five million, three hundred ten thousand, two hundred twenty-one".