620651571557 has 4 divisors (see below), whose sum is σ = 620965192320. Its totient is φ = 620337950796.

The previous prime is 620651571523. The next prime is 620651571619. The reversal of 620651571557 is 755175156026.

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.

It is a cyclic number.

It is not a de Polignac number, because 620651571557 - 2⁶ = 620651571493 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 (620651571517) 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, 156807413 + ... + 156811370.

It is an arithmetic number, because the mean of its divisors is an integer number (155241298080).

Almost surely, 2^620651571557 is an apocalyptic number.

It is an amenable number.

620651571557 is a deficient number, since it is larger than the sum of its proper divisors (313620763).

620651571557 is a wasteful number, since it uses less digits than its factorization.

620651571557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313620762.

The product of its (nonzero) digits is 2205000, while the sum is 50.

The spelling of 620651571557 in words is "six hundred twenty billion, six hundred fifty-one million, five hundred seventy-one thousand, five hundred fifty-seven".