61570643621 has 4 divisors (see below), whose sum is σ = 62732353932. Its totient is φ = 60408933312.

The previous prime is 61570643587. The next prime is 61570643623. The reversal of 61570643621 is 12634607516.

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 47072075521 + 14498568100 = 216961^2 + 120410^2 .

It is a cyclic number.

It is not a de Polignac number, because 61570643621 - 2³⁴ = 44390774437 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 (61570643623) 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, 580855076 + ... + 580855181.

It is an arithmetic number, because the mean of its divisors is an integer number (15683088483).

Almost surely, 2^61570643621 is an apocalyptic number.

It is an amenable number.

61570643621 is a deficient number, since it is larger than the sum of its proper divisors (1161710311).

61570643621 is a wasteful number, since it uses less digits than its factorization.

61570643621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161710310.

The product of its (nonzero) digits is 181440, while the sum is 41.

The spelling of 61570643621 in words is "sixty-one billion, five hundred seventy million, six hundred forty-three thousand, six hundred twenty-one".