205215610551 has 16 divisors (see below), whose sum is σ = 331104178944. Its totient is φ = 110368059264.

The previous prime is 205215610541. The next prime is 205215610559. The reversal of 205215610551 is 155016512502.

It is not a de Polignac number, because 205215610551 - 2⁷ = 205215610423 is a prime.

It is a super-2 number, since 2×205215610551² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205215610559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 287416465 + ... + 287417178.

It is an arithmetic number, because the mean of its divisors is an integer number (20694011184).

Almost surely, 2^205215610551 is an apocalyptic number.

205215610551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

205215610551 is a deficient number, since it is larger than the sum of its proper divisors (125888568393).

205215610551 is a wasteful number, since it uses less digits than its factorization.

205215610551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574833670.

The product of its (nonzero) digits is 15000, while the sum is 33.

The spelling of 205215610551 in words is "two hundred five billion, two hundred fifteen million, six hundred ten thousand, five hundred fifty-one".