951111661 has 4 divisors (see below), whose sum is σ = 951190300. Its totient is φ = 951033024.

The previous prime is 951111649. The next prime is 951111737. The reversal of 951111661 is 166111159.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 166111159 = 29 ⋅5727971.

It can be written as a sum of positive squares in 2 ways, for example, as 437228100 + 513883561 = 20910^2 + 22669^2 .

It is a cyclic number.

It is not a de Polignac number, because 951111661 - 2¹¹ = 951109613 is a prime.

It is a super-2 number, since 2×951111661² = 1809226783380357842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (951111611) 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, 16926 + ... + 46783.

It is an arithmetic number, because the mean of its divisors is an integer number (237797575).

Almost surely, 2^951111661 is an apocalyptic number.

It is an amenable number.

951111661 is a deficient number, since it is larger than the sum of its proper divisors (78639).

951111661 is a wasteful number, since it uses less digits than its factorization.

951111661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78638.

The product of its digits is 1620, while the sum is 31.

The square root of 951111661 is about 30840.0982650834. The cubic root of 951111661 is about 983.4308671107.

The spelling of 951111661 in words is "nine hundred fifty-one million, one hundred eleven thousand, six hundred sixty-one".