651999942 has 80 divisors (see below), whose sum is σ = 1599052752. Its totient is φ = 196922880.

The previous prime is 651999941. The next prime is 651999949. The reversal of 651999942 is 249999156.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651999941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1056418 + ... + 1057034.

Almost surely, 2^651999942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651999942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799526376).

651999942 is an abundant number, since it is smaller than the sum of its proper divisors (947052810).

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

651999942 is a wasteful number, since it uses less digits than its factorization.

651999942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235 (or 1226 counting only the distinct ones).

The product of its digits is 1574640, while the sum is 54.

The square root of 651999942 is about 25534.2895338797. The cubic root of 651999942 is about 867.1266203163.

The spelling of 651999942 in words is "six hundred fifty-one million, nine hundred ninety-nine thousand, nine hundred forty-two".