661012023 has 16 divisors (see below), whose sum is σ = 1008483840. Its totient is φ = 377260896.

The previous prime is 661011991. The next prime is 661012031. The reversal of 661012023 is 320210166.

It is a happy number.

It is not a de Polignac number, because 661012023 - 2⁵ = 661011991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661012063) 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, 1140 + ... + 36377.

It is an arithmetic number, because the mean of its divisors is an integer number (63030240).

Almost surely, 2^661012023 is an apocalyptic number.

661012023 is a deficient number, since it is larger than the sum of its proper divisors (347471817).

661012023 is a wasteful number, since it uses less digits than its factorization.

661012023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38366.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 661012023 is about 25710.1540835523. The cubic root of 661012023 is about 871.1035553390.

Adding to 661012023 its reverse (320210166), we get a palindrome (981222189).

The spelling of 661012023 in words is "six hundred sixty-one million, twelve thousand, twenty-three".