997621761 has 16 divisors (see below), whose sum is σ = 1416852864. Its totient is φ = 622205184.

The previous prime is 997621699. The next prime is 997621789. The reversal of 997621761 is 167126799.

It is a happy number.

It is not a de Polignac number, because 997621761 - 2¹⁸ = 997359617 is a prime.

It is a super-2 number, since 2×997621761² = 1990498356041482242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 997621761.

It is not an unprimeable number, because it can be changed into a prime (997622761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50050 + ... + 67083.

It is an arithmetic number, because the mean of its divisors is an integer number (88553304).

It is a Proth number, since it is equal to 30445 ⋅ 2¹⁵ + 1 and 30445 < 2¹⁵.

Almost surely, 2^997621761 is an apocalyptic number.

It is an amenable number.

997621761 is a deficient number, since it is larger than the sum of its proper divisors (419231103).

997621761 is a wasteful number, since it uses less digits than its factorization.

997621761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117320.

The product of its digits is 285768, while the sum is 48.

The square root of 997621761 is about 31585.1509573724. The cubic root of 997621761 is about 999.2066243883.

The spelling of 997621761 in words is "nine hundred ninety-seven million, six hundred twenty-one thousand, seven hundred sixty-one".