215769961 has 4 divisors (see below), whose sum is σ = 235385424. Its totient is φ = 196154500.

The previous prime is 215769959. The next prime is 215769973. The reversal of 215769961 is 169967512.

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 215769961 - 2¹ = 215769959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215769901) 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, 9807715 + ... + 9807736.

It is an arithmetic number, because the mean of its divisors is an integer number (58846356).

Almost surely, 2^215769961 is an apocalyptic number.

It is an amenable number.

215769961 is a deficient number, since it is larger than the sum of its proper divisors (19615463).

215769961 is a wasteful number, since it uses less digits than its factorization.

215769961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19615462.

The product of its digits is 204120, while the sum is 46.

The square root of 215769961 is about 14689.1102861950. The cubic root of 215769961 is about 599.7869252668.

The spelling of 215769961 in words is "two hundred fifteen million, seven hundred sixty-nine thousand, nine hundred sixty-one".