61402640 has 160 divisors (see below), whose sum is σ = 170989056. Its totient is φ = 20275200.

The previous prime is 61402637. The next prime is 61402651. The reversal of 61402640 is 4620416.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 406565 + ... + 406715.

Almost surely, 2^61402640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61402640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85494528).

61402640 is an abundant number, since it is smaller than the sum of its proper divisors (109586416).

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

61402640 is a wasteful number, since it uses less digits than its factorization.

61402640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 61402640 is about 7835.9836651182. The cubic root of 61402640 is about 394.5139350484.

The spelling of 61402640 in words is "sixty-one million, four hundred two thousand, six hundred forty".