1011945551 has 4 divisors (see below), whose sum is σ = 1012070112. Its totient is φ = 1011820992.

The previous prime is 1011945547. The next prime is 1011945581. The reversal of 1011945551 is 1555491101.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1011945551 - 2² = 1011945547 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 (1011945581) 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 3 ways as a sum of consecutive naturals, for example, 49175 + ... + 66648.

It is an arithmetic number, because the mean of its divisors is an integer number (253017528).

Almost surely, 2^1011945551 is an apocalyptic number.

1011945551 is a deficient number, since it is larger than the sum of its proper divisors (124561).

1011945551 is an equidigital number, since it uses as much as digits as its factorization.

1011945551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124560.

The product of its (nonzero) digits is 4500, while the sum is 32.

The square root of 1011945551 is about 31811.0916348371. The cubic root of 1011945551 is about 1003.9660995919.

The spelling of 1011945551 in words is "one billion, eleven million, nine hundred forty-five thousand, five hundred fifty-one".