155407653421 has 4 divisors (see below), whose sum is σ = 156074639292. Its totient is φ = 154740667552.

The previous prime is 155407653403. The next prime is 155407653451. The reversal of 155407653421 is 124356704551.

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 32109056100 + 123298597321 = 179190^2 + 351139^2 .

It is a cyclic number.

It is not a de Polignac number, because 155407653421 - 2³³ = 146817718829 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 (155407653451) 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, 333492586 + ... + 333493051.

It is an arithmetic number, because the mean of its divisors is an integer number (39018659823).

Almost surely, 2^155407653421 is an apocalyptic number.

It is an amenable number.

155407653421 is a deficient number, since it is larger than the sum of its proper divisors (666985871).

155407653421 is an equidigital number, since it uses as much as digits as its factorization.

155407653421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666985870.

The product of its (nonzero) digits is 504000, while the sum is 43.

The spelling of 155407653421 in words is "one hundred fifty-five billion, four hundred seven million, six hundred fifty-three thousand, four hundred twenty-one".