997251890 has 16 divisors (see below), whose sum is σ = 1795502808. Its totient is φ = 398800896.

The previous prime is 997251847. The next prime is 997251929. The reversal of 997251890 is 98152799.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 677092441 + 320159449 = 26021^2 + 17893^2 .

It is a super-2 number, since 2×997251890² = 1989022664217144200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 39944 + ... + 59916.

Almost surely, 2^997251890 is an apocalyptic number.

997251890 is a deficient number, since it is larger than the sum of its proper divisors (798250918).

997251890 is a wasteful number, since it uses less digits than its factorization.

997251890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24973.

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 997251890 is about 31579.2952739608. The cubic root of 997251890 is about 999.0831229267.

The spelling of 997251890 in words is "nine hundred ninety-seven million, two hundred fifty-one thousand, eight hundred ninety".