997401690 has 36 divisors (see below), whose sum is σ = 2594023614. Its totient is φ = 265893888.

The previous prime is 997401649. The next prime is 997401707. The reversal of 997401690 is 96104799.

It can be written as a sum of positive squares in 3 ways, for example, as 702833121 + 294568569 = 26511^2 + 17163^2 .

It is a super-2 number, since 2×997401690² = 1989620262429712200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 297946 + ... + 301274.

Almost surely, 2^997401690 is an apocalyptic number.

997401690 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

997401690 is an abundant number, since it is smaller than the sum of its proper divisors (1596621924).

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

997401690 is an equidigital number, since it uses as much as digits as its factorization.

997401690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6671 (or 3339 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The square root of 997401690 is about 31581.6669921016. Note that the first 3 decimals coincide. The cubic root of 997401690 is about 999.1331454470.

The spelling of 997401690 in words is "nine hundred ninety-seven million, four hundred one thousand, six hundred ninety".