202106561565551 has 4 divisors (see below), whose sum is σ = 205532096507400. Its totient is φ = 198681026623704.

The previous prime is 202106561565533. The next prime is 202106561565583. The reversal of 202106561565551 is 155565165601202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-202106561565551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 202106561565551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202106561567551) 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, 1712767470836 + ... + 1712767470953.

It is an arithmetic number, because the mean of its divisors is an integer number (51383024126850).

Almost surely, 2^{202106561565551} is an apocalyptic number.

202106561565551 is a deficient number, since it is larger than the sum of its proper divisors (3425534941849).

202106561565551 is an equidigital number, since it uses as much as digits as its factorization.

202106561565551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3425534941848.

The product of its (nonzero) digits is 2700000, while the sum is 50.

The spelling of 202106561565551 in words is "two hundred two trillion, one hundred six billion, five hundred sixty-one million, five hundred sixty-five thousand, five hundred fifty-one".