245551420153021 has 4 divisors (see below), whose sum is σ = 245681410319100. Its totient is φ = 245421429986944.

The previous prime is 245551420153009. The next prime is 245551420153073. The reversal of 245551420153021 is 120351024155542.

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 100708028844921 + 144843391308100 = 10035339^2 + 12035090^2 .

It is a cyclic number.

It is not a de Polignac number, because 245551420153021 - 2¹⁹ = 245551419628733 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 (245551420153121) 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, 64995080206 + ... + 64995083983.

It is an arithmetic number, because the mean of its divisors is an integer number (61420352579775).

Almost surely, 2^{245551420153021} is an apocalyptic number.

It is an amenable number.

245551420153021 is a deficient number, since it is larger than the sum of its proper divisors (129990166079).

245551420153021 is a wasteful number, since it uses less digits than its factorization.

245551420153021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129990166078.

The product of its (nonzero) digits is 240000, while the sum is 40.

The spelling of 245551420153021 in words is "two hundred forty-five trillion, five hundred fifty-one billion, four hundred twenty million, one hundred fifty-three thousand, twenty-one".