997091972 has 6 divisors (see below), whose sum is σ = 1744910958. Its totient is φ = 498545984.

The previous prime is 997091971. The next prime is 997091989. The reversal of 997091972 is 279190799.

It can be written as a sum of positive squares in only one way, i.e., 596531776 + 400560196 = 24424^2 + 20014^2 .

It is not an unprimeable number, because it can be changed into a prime (997091971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124636493 + ... + 124636500.

It is an arithmetic number, because the mean of its divisors is an integer number (290818493).

Almost surely, 2^997091972 is an apocalyptic number.

It is an amenable number.

997091972 is a deficient number, since it is larger than the sum of its proper divisors (747818986).

997091972 is a wasteful number, since it uses less digits than its factorization.

997091972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249272997 (or 249272995 counting only the distinct ones).

The product of its (nonzero) digits is 642978, while the sum is 53.

The square root of 997091972 is about 31576.7631653404. The cubic root of 997091972 is about 999.0297161871.

The spelling of 997091972 in words is "nine hundred ninety-seven million, ninety-one thousand, nine hundred seventy-two".