997720042 has 16 divisors (see below), whose sum is σ = 1667371392. Its totient is φ = 443859520.

The previous prime is 997720007. The next prime is 997720043. The reversal of 997720042 is 240027799.

It is a junction number, because it is equal to n+sod(n) for n = 997719977 and 997720004.

It is not an unprimeable number, because it can be changed into a prime (997720043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 481423 + ... + 483490.

It is an arithmetic number, because the mean of its divisors is an integer number (104210712).

Almost surely, 2^997720042 is an apocalyptic number.

997720042 is a deficient number, since it is larger than the sum of its proper divisors (669651350).

997720042 is a wasteful number, since it uses less digits than its factorization.

997720042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964973.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 997720042 is about 31586.7067292556. The cubic root of 997720042 is about 999.2394356886.

The spelling of 997720042 in words is "nine hundred ninety-seven million, seven hundred twenty thousand, forty-two".