11961551 has 16 divisors (see below), whose sum is σ = 14076480. Its totient is φ = 9953280.

The previous prime is 11961527. The next prime is 11961563. The reversal of 11961551 is 15516911.

It is a cyclic number.

It is not a de Polignac number, because 11961551 - 2⁶ = 11961487 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 (11961151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46415 + ... + 46671.

It is an arithmetic number, because the mean of its divisors is an integer number (879780).

Almost surely, 2^11961551 is an apocalyptic number.

11961551 is a deficient number, since it is larger than the sum of its proper divisors (2114929).

11961551 is a wasteful number, since it uses less digits than its factorization.

11961551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434.

The product of its digits is 1350, while the sum is 29.

The square root of 11961551 is about 3458.5475275034. The cubic root of 11961551 is about 228.6980695718.

The spelling of 11961551 in words is "eleven million, nine hundred sixty-one thousand, five hundred fifty-one".