51238890 has 24 divisors (see below), whose sum is σ = 133221348. Its totient is φ = 13663680.

The previous prime is 51238879. The next prime is 51238897. The reversal of 51238890 is 9883215.

It can be written as a sum of positive squares in 2 ways, for example, as 45522009 + 5716881 = 6747^2 + 2391^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (51238897) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 284571 + ... + 284750.

Almost surely, 2^51238890 is an apocalyptic number.

51238890 is an abundant number, since it is smaller than the sum of its proper divisors (81982458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51238890 is a wasteful number, since it uses less digits than its factorization.

51238890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569334 (or 569331 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 51238890 is about 7158.1345335220. The cubic root of 51238890 is about 371.4210992439.

The spelling of 51238890 in words is "fifty-one million, two hundred thirty-eight thousand, eight hundred ninety".