1290991845 has 96 divisors (see below), whose sum is σ = 2480039424. Its totient is φ = 568339200.

The previous prime is 1290991799. The next prime is 1290991847. The reversal of 1290991845 is 5481990921.

It is not a de Polignac number, because 1290991845 - 2¹⁵ = 1290959077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1290991794 and 1290991803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1290991847) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1867950 + ... + 1868640.

It is an arithmetic number, because the mean of its divisors is an integer number (25833744).

Almost surely, 2^1290991845 is an apocalyptic number.

1290991845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1290991845 is a deficient number, since it is larger than the sum of its proper divisors (1189047579).

1290991845 is a wasteful number, since it uses less digits than its factorization.

1290991845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803 (or 790 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 48.

The square root of 1290991845 is about 35930.3749632536. The cubic root of 1290991845 is about 1088.8661567612.

The spelling of 1290991845 in words is "one billion, two hundred ninety million, nine hundred ninety-one thousand, eight hundred forty-five".